Alpha-1 antitrypsin deficiency with genotype MZ is one of the most common — and most overlooked — inherited conditions in the world. We bring patients, clinicians and researchers together to change that.
To advance how patients and clinicians worldwide understand alpha-1 antitrypsin deficiency with the MZ genotype — the type that has been quietly hiding in plain sight.
For decades, MZ carriers were waved off as "just carriers." A growing body of research tells a different story: when exposed to the wrong triggers, MZ individuals face real, measurable risks across the lungs, liver, nervous system and immune response. We connect those dots, source by source, study by study.
Read our full mission →Alpha-1 MZ rarely announces itself. It surfaces as a constellation of second- and third-order symptoms — easy to misattribute, easy to miss.
A meaningful share of the misfolded Z protein stays trapped inside hepatocytes, eroding the liver's other functions.
When the body's natural "off-switch" for inflammation is at half-strength, the alveolar walls slowly pay the price.
Downstream of liver and gut imbalances, B12 absorption falters — and neuropathy can follow.
Panniculitis and slow wound healing are uncommon, but unmistakable signals when they appear.
Every completed questionnaire makes the picture clearer. Submissions are anonymous unless you choose otherwise, and feed directly into our research dataset.
We are a small team of patients, clinicians and engineers who got tired of hearing "you're just a carrier." The Alpha-1 MZ Foundation exists because the medical literature was already quietly catching up — somebody just needed to gather it in one place.
Think of us as a librarian with a stethoscope. We do not provide medical advice; we read peer-reviewed papers, pair them with real clinical cases from the MZ community, and translate the result into something a patient or a busy GP can actually use.
When the dots line up, we say so. When they do not, we say that too. Our work is patient-funded, independent, and free for anyone to read.
The foundation is run by a small international team of patients, advocates and researchers. Together we cover patient outreach, clinical research, communications, policy advocacy, and the day-to-day work of running an independent foundation.
Frans Frielink lives in Belgium and has a research and development background, with over 40 years of experience in the semiconductor industry leading engineering, marketing and business development. He has shaped the direction of multiple companies, helped drive WiFi to a massive worldwide success, and built GreenPeak into a market leader in the fast-growing smart home and IoT space.
Frans holds patents in several fields and is currently active as chairman, board member and advisor for companies across a range of emerging technologies and markets. He is an Alpha-1 MZ himself, and started studying the medical literature in 2020 — work that allowed him to diagnose and resolve his own medical issues. He is the founding father of the Alpha-1 MZ Foundation.
“My personal journey with Alpha-1 began when several family members received their diagnosis. Initially, my focus was on reimbursement options for augmentation therapy, because of my previous work with the National Care Institute.
As I delved deeper into Alpha-1, I discovered a significant lack of awareness and understanding around this condition. The fact that so many people remain undiagnosed or receive a late diagnosis, coupled with the realisation of its widespread prevalence and the multifaceted role of antitrypsin in the body, sparked my interest in the relationship between Alpha-1 and autoimmune diseases.
Throughout my career I have had the privilege of contributing to the fields of social security and healthcare in various capacities. I have authored several books on these topics and served as the publisher of the Pharmaco-therapeutic Compass (Farmacotherapeutisch Kompas) in the Netherlands.
My professional journey began as a university researcher, followed by various research leadership positions at the Ministry of Social Affairs and the National Care Institute. I have also actively participated in board functions, including serving as a trustee of the Lansbury House Trust Fund.
I am excited to be part of the Alpha-1 MZ Foundation Board. I firmly believe this organisation is a vital platform for advancing Alpha-1 research, increasing awareness, and ultimately improving the lives of patients.”
Margaret is a long-time Alpha-1 patient advocate with a lifetime of familial and community experience. She advocates broadly — alongside the Alpha-1 MZ Foundation, the Global Liver Institute, the Alpha-1 Advocacy & Action Coalition and many other patient groups and stakeholders — keeping current on research, clinical trials, care pathways and policy on behalf of the global Alpha-1 community. Her passion is serving the Alpha-1 community.
Dr. Laura K. Bonebrake (Anderson) is an obstetrician-gynecologist practising in St. Louis, Missouri, with hospital affiliations across the area. She earned her medical degree at Creighton University School of Medicine and has more than a decade of clinical experience. Her research interests centre on intrahepatic cholestasis of pregnancy and its overlap with other liver disorders, with a particular focus on how hormones interact with liver disease. She serves on the Board of Directors of ICP Care, a non-profit patient advocacy organisation that raises awareness of ICP among both patients and clinicians. Her connection to liver disease is also personal: she experienced ICP in all of her pregnancies, which ultimately led to her own Alpha-1 MZ diagnosis.
Diana first encountered alpha-1 antitrypsin deficiency in the early 1990s, when her father effectively diagnosed himself through the Medical University of South Carolina after his physician declined to order the test. He turned out to be a severely affected ZZ — Diana helped him pursue a lung transplant evaluation, but he was ultimately not accepted as a candidate, and he passed away from AATD-related lung disease in 1998. As an MZ herself, Diana has now been researching AATD for around three decades. She holds a BSc in biochemistry and an MSc in holistic nutrition — backgrounds that help her read the primary literature and address health issues she believes are tied to AATD where conventional medicine has had little to offer. Because medical options for the MZ condition are limited, nutrition and lifestyle take on outsized importance for quality of life. Her aim is to be useful to the MZ community by sharing what she has learned through her education, her research and her own experience as an MZ Alpha.
Fiona is a tutor at Queen's University Belfast in the School of Electronics, Electrical Engineering and Computer Science (EEECS). She holds a PhD in chemistry, a BSc in biochemistry, a postgraduate diploma in chemistry and a Master's in computing and information systems. Her interdisciplinary career spans pharmaceutical science, technology and research — including time at Pfizer in drug metabolism and early bioinformatics work on gene expression and peptide-based therapies. Alongside that academic and industry background, she brings a deep personal interest in how emerging technologies can support genomics-informed healthcare, lifestyle choices and personalised medicine. As a mother of four, she pairs professional experience with lived insight, and she is a passionate advocate for greater recognition of overlooked genetic traits — such as the MZ Alpha-1 antitrypsin genotype — and their potential role in drug response and long-term health.
European Parliament. The foundation has been invited by ELPA — the European Liver Patients' Association — to present at the European Parliament alongside other rare disease representatives. The aim is to make the impact of Alpha-1 antitrypsin deficiency, particularly the MZ genotype, visible in European healthcare policy and research agendas. Of the 35 million MZ carriers worldwide, only a small fraction (~0.02%) are currently diagnosed.
October 2025 webinar. The foundation hosted a successful international webinar in October 2025. It opened with an introduction by Frans Frielink and a presentation by Professor Gerry McElvaney titled "Delineating the risk of lung disease in MZ alpha-1 antitrypsin deficiency", followed by Frans on Alpha-1 MZ liver-related morbidities and mechanics. The recording is split per speaker on the foundation's YouTube channel.
Newsletters and Substack. The foundation publishes regular educational newsletters. After passing 500 subscribers in 2025, the distribution moved from email to Substack so the full archive remains browsable in one place. New issues continue to appear there.
Thirty-five million people carry the MZ genotype. Far too many of them are unwell without ever being told why. The work below is how we plan to change that — one piece at a time.
Working with governments, medical bodies and healthcare organisations so the real impact on Alpha-1 MZ patients — and SZ as well — is finally acknowledged in care guidelines.
Building communities and support networks across borders and languages so no MZ patient anywhere has to face this alone.
Giving patients and families the knowledge and confidence to advocate for better care — through our newsletters, webinars and plain-language explainers.
Supporting biobanks, biomarker work and underserved areas like intrahepatic cholestasis of pregnancy, where mothers and babies are directly affected.
Alpha-1 antitrypsin is the body's anti-inflammatory dimmer switch. When the MZ genotype keeps roughly half of it from reaching the bloodstream, the consequences cascade.
In an MZ liver, the "M" half of the protein folds correctly and slips out into the bloodstream. The "Z" half folds wrong and gets stuck inside the hepatocyte like a misshapen package that won't fit through the door. A fraction of those packages pile up as polymers — and polymers, over time, are associated with liver disease.
The knock-on effect matters even more than the storage problem. A liver busy dealing with stuck protein has less capacity left over for everything else it's supposed to do — bile production, detoxification, B12 storage. And because livers shed roughly a third of their working capacity by retirement age, MZ symptoms tend to surface in mid-to-late adulthood.
Histology tells an even sharper story. The liver is built from hexagonal lobules; under normal conditions, the "professional" AAT-producing cells are the periportal hepatocytes at the edge of each lobule, with the midlobular and centrolobular cells joining in only when the body asks for more. In MZ livers, AAT staining is positive across all the hepatocytes of adjacent lobules — and not only in hepatocytes, but also in the endothelial cells of the portal vessels. The intensity grades from a fully positive cytoplasm at the periportal zone down through the midlobular and pericentral zones, where characteristic crescent and double-row patterns appear. The conclusion is unambiguous: the term "carrier" no longer applies — every Pi*MZ individual undergoes some degree of intrahepatic AAT storage, and that storage predisposes the liver to damage and reduced reserve capacity.
This is sometimes called the Recruitment-Secretory Block (RSB) model, after the Callea group's work. It explains the apparently paradoxical observation that MZs can have intermediate or near-normal serum AAT levels while still accumulating significant intrahepatic storage.
Picture neutrophil elastase as a demolition crew the body sends in to clear infection. Useful - until it is time to stop. Alpha-1 antitrypsin is the foreman who calls the crew off. With only half the foremen on shift, the demolition runs longer than it should, and the elastic walls of the air sacs gradually take the damage.
Over years, that imbalance can lead to emphysema, particularly in MZ individuals exposed to tobacco smoke or polluted, dusty work environments. There is also a growing body of evidence linking AAT levels to bronchiectasis, including animal and human studies showing AAT protective role against pulmonary infection and inflammation.
In the bronchiectasis research specifically, transgenic mice expressing human AAT in the lungs survived Pseudomonas aeruginosa-induced pneumonia at much higher rates than controls, with less lung tissue damage, lower bacterial load and lower circulating cytokines. A separate human study found that patients with humoral immunodeficiencies who developed bronchiectasis had lower median AAT levels than those who did not.
The neurological symptoms our community reports are rarely a direct effect of the missing protein. They are usually a chain reaction: a stressed liver makes less bile acid, the small intestine's bacterial balance drifts (SIBO is common), B12 absorption falters, and nerves further from the spine — fingers, toes — pay the price first.
It is the kind of trail that takes years to walk backward. We point patients toward the right tests early — ferritin, B12, folate, intrinsic factor antibodies — so they don't have to.
B12 deficiency in its early stages is typically asymptomatic, and diagnosis is often delayed because clinicians wait for anaemia to appear. By the time it does, neurological damage may have already started. The standard clinical treatment for severe B12 deficiency is intramuscular hydroxocobalamin — usually 1000 µg several times a week initially in the presence of neurological symptoms, then 1000 µg every two months as maintenance. Important MZ-specific caveat: these standard schedules do not account for liver involvement. Because B12 is processed and stored in the liver, an MZ patient with reduced hepatic capacity may not be able to bridge the standard intervals between doses, which can call for a lower amount per dose given more frequently. Always discuss B12 treatment with a doctor who is aware of your Alpha-1 status.
Alpha-1 mostly affects the lungs and liver, but the skin can show its own warning signs. The most distinctive is panniculitis: painful red nodules or plaques that often appear on the legs, thighs or buttocks and may ulcerate under pressure or trauma.
Less dramatic but more common: slower wound healing, easier bruising, and a higher susceptibility to bacterial and fungal skin infections. AAT also helps protect elastin, so very long-running deficiency may contribute to premature loss of skin firmness.
A subtle theme reported across the MZ community is connective tissue trouble — tendon sheaths that inflame too easily, ligaments that take longer than they should to recover, joints that flare without an obvious mechanical reason. Alpha-1 antitrypsin is part of the protective screen for these tissues, and a long-running half-strength supply seems to leave them more vulnerable to wear and inflammation.
It is one of the harder MZ patterns to pin down because the symptoms look exactly like the ordinary aches of getting older. The tell is when those aches do not respond to the things that usually fix them — and when an MZ liver also rules out the most common painkillers.
Alpha-1 antitrypsin is more than a lung shield. It also helps regulate inflammation across the whole body — keeping immune responses proportionate, dialled-down once a threat has passed. With half the usual supply, the brake pedal is softer than it should be, and the immune system can run hot for longer than it needs to.
The community pattern that follows is a higher-than-average rate of autoimmune diagnoses: thyroid issues, gut inflammation, joint and connective tissue conditions, the occasional skin disorder. None of this is universal, but it shows up far too often in MZ histories to be a coincidence.
Vitamin B12 absorption is a delicate handover. It needs enough stomach acid, enough intrinsic factor, a healthy small intestine and a working liver to store it afterwards. An MZ liver makes less bile acid; the small intestine's bacterial balance shifts; and the handover starts to fail. The deficit can creep in for years before anyone runs the test that would catch it.
When the level finally drops far enough, the symptoms are unmistakable: tingling and numbness in the fingers and toes, brain fog, fatigue that does not respond to sleep, anaemia. Treatment is straightforward — injections or high-dose oral B12 — but the diagnosis often takes years longer than it should because the early symptoms look like everything else.
If you have an MZ diagnosis and any of these symptoms, asking your doctor for a B12, folate, ferritin and intrinsic-factor antibody panel is a reasonable starting point.
Pregnancy puts a substantial extra load on the liver. Hormone levels rise sharply, bile flow shifts, and a liver with reduced functional reserve has to work harder to keep up. For some MZ women, that extra load is the moment a previously quiet condition starts to make noise.
The clearest signal is intrahepatic cholestasis of pregnancy (ICP) — a slowdown of bile flow that causes intense itching, especially on the palms and soles, and that carries real risks for the baby if untreated. Recent population data suggest that MZ individuals account for a meaningful share of ICP cases, which is exactly the kind of overlooked link our work exists to highlight.
If you are MZ and pregnant — or planning to be — flagging this with your obstetrician early is worth the conversation. ICP is treatable, but only once it is recognised.
The current standard of care for severe Alpha-1 — augmentation therapy with weekly intravenous infusions of pooled-plasma AAT — has been around since the late 1980s. It slows lung disease in ZZ patients. Whether it benefits MZ individuals is still debated, and most clinical guidelines do not recommend it for them, though a small number of MZs with severe symptoms do receive it.
More interesting things are coming. Several biotech companies are developing RNA therapies that lower production of the misfolded Z protein in the liver. Prime Medicine has announced a programme to fix the SERPINA1 mutation directly in liver cells using prime editing — a precise "search and replace" approach to DNA — with first human trials expected around 2027. None of these are a cure today, but for the first time in decades the pipeline contains real candidates that target the root cause rather than the downstream damage.
A recent finding from our own community is also reshaping how we think about MZ liver health: a quantitative breath test (LiMAx) used in three Pi*MZ participants showed functional liver capacity reduced by roughly 40–60% compared with healthy controls, even with normal-looking standard liver enzymes. This is a small, early signal — but it suggests that the liver's actual working reserve in MZs may be measurably lower than routine bloodwork would imply, and that a "liver-protective" approach to diet and medication is warranted.
From the small correlation work our community has done so far, the most frequently reported issues cluster like this:
Lung symptoms are well documented elsewhere and were left out of that early correlation work.
You inherit one allele from each parent. The combination determines how much functional protein your body produces.
The standard, fully functional version. No deficiency.
A mild reduction. Usually well tolerated.
Our focus. Half the usable protein, with risk that depends heavily on lifestyle and exposure.
The severe, well-recognised form of the deficiency.
The familiar M / S / Z labels come from a 1960s lab technique called isoelectric focusing — a kind of fingerprint based on how the protein moves through a gel. The DNA underneath tells a much richer story. Over a hundred SERPINA1 variants have been documented, with very different effects on AAT levels, lung function, liver health and more. Our variants table lists every well-characterised allele, with mechanism, organ effects and a direct link to its position in the AAT protein structure.
Each row is a known mutation in the SERPINA1 gene that affects (or has been claimed to affect) the alpha-1 antitrypsin protein. Sort any column. Filter by deficiency mechanism. Click a variant to see its position highlighted in the AAT protein structure on AlphaFold, or jump to its entry in UniProt's continuously-curated variant viewer.
For education, not clinical decision-making. Population frequencies and mechanisms are reproduced from Seixas & Marques (2021), the canonical published overview. Where the source classifies a variant's effect as "Unknown" or did not assess a specific organ, this table reflects that honestly rather than guess. Treatment decisions should always involve a clinician familiar with your specific case.
| Allele | Mutation | Exon | Mechanism | AAT level | Lung | Liver | Skin | GI | Links |
|---|
Source: Seixas S & Marques P. Known mutations at the cause of alpha-1 antitrypsin deficiency: an updated overview of SERPINA1 variation spectrum. Appl Clin Genet. 2021;14:173–194. doi:10.2147/TACG.S257511. Population frequencies from gnomAD as cited in source. The canonical, continuously-updated catalogue is at UniProt P01009. AlphaFold structures are predicted; for variants with experimentally determined structures, refer to the corresponding PDB entry.
You are not alone. Roughly thirty-five million people share your genotype. Most of them have not been told. Here is what we wish someone had told us first.
If you have just been told that you have alpha-1 antitrypsin deficiency, the first thing to know is that there are roughly 35 million people worldwide with this genetic condition. The reason it is not better known is that it is very hard to diagnose from symptoms alone — most of us have seen many doctors before anyone joined the dots.
There are several types of alpha-1 antitrypsin deficiency. This foundation focuses on the MZ genotype because it is the most common one and the most under-recognised. The probability that you are MZ is quite high: about 4% of people of European heritage carry it. The four most common genotypes are:
Your genotype is settled by a simple genetic test. Ask your doctor — and if you cannot get one through your healthcare system, commercial home test kits exist as well.
Roughly half of your alpha-1 antitrypsin is usually enough for a full life — provided the rest of your environment cooperates. Clean air, no smoking, modest alcohol, and a diet your liver can keep up with. Think of it as driving a car with a smaller fuel tank: still goes everywhere, just needs more thoughtful refuelling.
The two highest-impact decisions you can make are simple and not new: do not smoke (your lungs are already short on the enzyme that protects them) and be careful with alcohol (your liver is already working with a partly-stuck protein that takes up space the rest of its functions need). On top of that, try to eat food your liver can process easily — smaller, more frequent meals over very large fatty ones, real food over ultra-processed.
Common over-the-counter painkillers like ibuprofen are particularly hard on an MZ liver. The same caution applies to high-dose supplements: more is not better when your liver is doing more of the work with less of the headroom. None of this is medical advice — but it is a conversation worth having with your doctor before you take anything new.
You cannot tell from symptoms alone. A simple genetic test will identify your genotype with certainty. Because Alpha-1 is inherited, anyone in your direct family deserves to know their result too — siblings, parents, children. A diagnosis in one branch of the family tree usually means the rest of the tree should at least be tested.
Within the foundation's ongoing correlation work — collecting symptom reports from MZ individuals worldwide — a clear set of recurring themes has emerged. Lung symptoms are deliberately not part of this study because they are already well documented elsewhere.
A growing body of research — including the foundation's own work alongside large population datasets — confirms that the MZ genotype carries real, measurable risk. Some of the most striking findings:
Functional cholestasis and whole-lobule polymer stress are reported as core liver mechanisms.
Bile duct disease is increased by 25%.
Gallstones are increased by 50%.
Liver transplantation is increased threefold; around 10% of all transplants are in MZ individuals.
Intrahepatic cholestasis during pregnancy is increased sevenfold; around 20% of ICP cases are linked to MZ.
Progression to liver decompensation is 1.8 times faster.
Functional liver capacity measured by LiMAx is reduced by between 40% and 60%, even without fibrosis and with normal-looking liver enzymes.
Biomarkers may show mild increases in bilirubin, ALP and GGT.
COPD risk is increased by 40%.
Bronchitis risk is increased by 20%.
Neuropathy is reported more often in MZ individuals.
Aneurysms are increased approximately 2.5-fold.
Coronary atherosclerosis is reported 16% lower.
Immune-system function may be reduced, while autoimmune patterns are increased.
Endocrine regulation may be reduced, with hormone dysregulation reported.
Reticulocytes are reduced by 31% on average, which can affect red-blood-cell production.
Absorption of minerals and vitamins (A, D, E, K and B12) is reduced, often in the context of SIBO.
Rheumatoid arthritis risk is increased threefold.
Osteoporosis risk is increased by 17%.
Prostatic hyperplasia is increased by 26%.
Sources: Kosinski et al., 2021; Fromme et al., 2021; Fawcett et al., 2021; Gedde-Dahl et al., 1980; W. I. Schievink et al., 1996; Callea et al., 2021; Sanders et al., 2019; Nakanishi T., Forgetta V., Handa T., et al., 2020; Peter H. Dixon et al., 2022.
If you have an MZ diagnosis and any of the symptoms above, the following lab panel is a reasonable starting point for a conversation with your doctor: vitamin B12, folate, ferritin, vitamin D, intrinsic-factor antibodies, total bile acids, ALT/AST/GGT, and a basic metabolic panel. None of this is a substitute for clinical judgement, but it gives a useful picture of where an MZ body is doing extra work — and where the gaps are most likely to show up first.
If you are pregnant or planning a pregnancy, mention your MZ status to your obstetrician early. Intrahepatic cholestasis of pregnancy is treatable, but only when it is recognised.
There are roughly 35 million MZ individuals worldwide, and active patient communities exist on Facebook and other platforms in many languages. Connecting with other patients is one of the most useful things you can do early on — both for practical advice and for the simple relief of finding people who recognise what you are describing. The foundation's Substack newsletter is one place to start; the broader Alpha-1 community across the Alpha-1 Foundation, ELPA, the Global Liver Institute and various national patient groups is another.
The Alpha-1 MZ Foundation is not a medical provider and does not give medical advice. Everything you read here is educational, sourced from peer-reviewed literature and patient experience, and is intended to help you have better-informed conversations with the clinicians who actually treat you.
A concise professional summary of the Pi*MZ genotype: one normal M allele and one Z allele in SERPINA1, producing both reduced circulating AAT and intrahepatic Z-AAT polymer retention.
Pi*MZ combines one normal M allele with one mutant Z allele in SERPINA1. The Z variant (Glu342Lys) misfolds and polymerizes inside cells, reducing secretion of functional alpha-1 antitrypsin while allowing polymers to accumulate in hepatocytes.
Circulating AAT is reduced by roughly 50% compared with Pi*MM, while a significant fraction of Z-AAT is retained in the liver endoplasmic reticulum. This creates both a systemic antiprotease deficit and a local hepatic storage burden.
Polymer accumulation drives chronic ER stress and impaired hepatocyte function. Under the Recruitment Secretory Block model, secretory and metabolic capacity can fall across the liver lobule, with functional impairment even without fibrosis or cirrhosis.
Reduced circulating AAT means reduced antiprotease protection. The clinical consequence is increased susceptibility to protease-mediated lung damage, particularly when environmental stressors such as smoke, dust or occupational exposure are present.
Pi*MZ should be framed as a risk genotype with both loss-of-function and gain-of-function pathology. Disease expression is not uniform, but the pattern is multi-system and clinically coherent.
The reported pattern is consistent with reduced hepatic functional reserve and cholestatic dysfunction: 40-60% reduced hepatic reserve capacity without fibrosis on LiMAx testing; around 10% of liver transplants and 2x faster decompensation; 20-25% of ICP cases; bile duct disease up 25% and gallstones up 50%; impaired absorption of A, D, E, K and B12; COPD/chronic bronchitis up 20-40%; rheumatoid arthritis up 3x; osteoporosis up 17%; and aneurysm risk up 2.5x.
Interested in the scientific literature about Alpha-1 Pi*MZ? The Library collects references and reading material for a deeper look.
Go to LibraryAlmost every person in this community has a story that begins with the wrong specialist and ends with a moment of recognition. Here are a few of them.
"Once I realised every one of my symptoms could be traced back to one missing protein, the picture finally stopped being a mystery."
After a private consultation with a German liver specialist confirmed the deficiency, Frans began treating his symptoms systematically — offloading the liver, supplementing B12, eliminating NSAIDs. The improvements compounded over the following years, and he recognised the same pattern in his father, who had stopped working in his mid-fifties with a similar constellation of complaints.
"It was as if a switch flipped — overnight I couldn't walk fifty yards without losing my breath."
Ken had spent decades sanding houses without a mask, an outdoorsman who hunted, fished and snowboarded into his fifties. When his breathing collapsed, his GP recognised the pattern and tested for AATD straight away. He was lucky in that one regard — most people in this community are not. He has since been on weekly augmentation therapy and stays in pulmonary rehab to keep moving.
"I was told I was 'just a carrier' for years. It turns out MZs can need infusions too."
After multiple inhalers failed to control her symptoms, a long drive to a specialist finally produced a different answer — and access to weekly augmentation therapy. Her pulmonologist now scans her every six months to track lung changes.
Stories like these are why we keep this foundation running.
Support our work →We publish regular updates on alpha-1 antitrypsin deficiency, focused on the MZ population — research highlights, advocacy progress, practical guidance for patients and clinicians. Browse the full archive below, sorted from newest to oldest.
Our current newsletter lives on Substack. Earlier issues are available as PDFs.
Loading…
Keep this work in your inbox — and keep it going.
Support the foundation →A curated set of the research, reviews and external resources we lean on most often. Some are foundation-hosted PDFs, some are open-access papers from peer-reviewed journals, and some are pages from sister organisations in the global Alpha-1 community. None of this is medical advice — it is the underlying material that informs everything else on this site.
Alpha-1 antitrypsin is a small protein produced mostly by the liver, and it does an enormous amount of work across the body. When the gene that codes for it carries the Z mutation, the protein is misfolded — part of it gets stuck in the liver instead of reaching the bloodstream, and the body's quiet anti-inflammatory off-switch is left half-broken. The downstream effects show up in the lungs, the liver itself, the gut, the nervous system, the connective tissues, the skin and even pregnancy. Each of the pages below walks through one organ system in plain language, with references to the underlying literature.
In Alpha-1 MZ individuals, around 85% of the Z-form protein is retained inside the liver cell, together with about 6% of the M-form. Roughly half of the usable M-form protein is what eventually reaches the bloodstream — about 50% of normal AAT levels. Most of the retained Z-form is broken down by the liver cell's quality-control systems, but a small fraction accumulates as ordered polymers, and those polymers are what link the MZ genotype to liver disease. The same shortage of circulating protein is what links it to the lung, gut, skin and connective tissue effects in the sections below.
Why MZs are vulnerable to emphysema and bronchiectasis when AAT can't switch off neutrophil elastase.
How the Z protein gets stuck in hepatocytes, the polymers that form there, and what it costs the rest of liver function.
The bile-acid chain — from impaired liver output through small intestinal bacterial overgrowth to malabsorption.
B12 absorption, peripheral neuropathy, and why neuro symptoms often turn out to be downstream of the gut.
Tendon sheath issues, ligament problems and what AAT has to do with the elastic structures that hold the body together.
Necrotising panniculitis, premature skin aging, and the inflammatory skin conditions linked to AAT deficiency.
Intrahepatic cholestasis of pregnancy (ICP) — why the Z allele has emerged as the leading single genetic risk factor.
Alpha-1 antitrypsin provides an antiprotease screen throughout the body, but its most important job is in the lungs, where it neutralises a serine protease called neutrophil elastase. Neutrophil elastase is essential for fighting infections — it's part of how the immune system breaks down foreign material — but it can also chew through healthy lung tissue if it isn't switched off. AAT is that off switch. Once an infection has been dealt with, AAT inhibits the elastase so it stops doing damage.
When circulating AAT is low, that switch doesn't engage cleanly. Protein breakdown in the supporting elastic structures of the lung — particularly in the walls of the air sacs (alveoli) — runs unopposed. Over years and decades, that progressive breakdown of alveolar walls is what we call emphysema, and it's accelerated dramatically by smoking and by occupational dust or chemical exposures. For an Alpha-1 MZ individual carrying roughly half the normal AAT level, the risk is real but the curve depends heavily on lifestyle: clean air and no tobacco buy back most of it.
Bronchiectasis — chronic dilation of the bronchial walls with persistent cough, sputum and frequent exacerbations — is also linked to AAT deficiency, though the strength of that link is still under active debate. Two suggestive studies stand out. In transgenic mice expressing human AAT in the lungs, mortality from Pseudomonas aeruginosa pneumonia was about 90% lower than in non-transgenic controls; giving exogenous human AAT to ordinary mice produced the same protective effect, with less lung tissue damage and lower bacterial concentrations in lungs and blood. In humans, among patients with humoral immunodeficiencies on gamma-globulin replacement therapy, those who had developed bronchiectasis tended to have lower median AAT levels than those who hadn't. Together these findings hint at a protective role for AAT in keeping the airways infection-resistant.
The practical takeaway for an Alpha-1 MZ individual is straightforward: clean air matters more for you than for the average person. Tobacco, occupational dust, solvent fumes, wood smoke, and any other airborne irritant takes a bigger toll on a lung that's missing half its anti-elastase shield. Annual lung function checks (spirometry) are worth asking your doctor about, especially if you've ever smoked or have an exposure history.
The liver is the root cause of most clinical issues in Alpha-1 MZ — and the picture gets sharper with age, when the liver has lost a meaningful share of its working capacity. The liver synthesises AAT according to your genotype. In an MZ individual the M-form is folded correctly and exported into the bloodstream as it should be, but the Z-form is misfolded and can't leave the hepatocyte. It gets stuck inside the liver cell.
In numbers: roughly 85% of the Z-form is retained inside hepatocytes, together with about 6% of the M-form. About 48% of the M-form makes it out and into the bloodstream — which is why a typical MZ ends up with around half of normal circulating AAT. Of the retained Z-form, around 70% is degraded by the liver cell's intracellular quality-control machinery. The remaining 15% accumulates as ordered polymers, and those polymers are what links the MZ genotype to liver disease. They are slow, quiet, and they build up over decades.
A bit of histology: the liver is built out of lobules — roughly hexagonal units, each surrounded by branches of the hepatic artery and the portal vein, draining inward through capillary-like sinusoids that exchange material directly with the hepatocytes, and out via a central vein into the hepatic vein. In normal conditions, AAT synthesis is mostly handled by the periportal hepatocytes, the "professional" protein-synthesisers. Under stimulation — inflammation, hormonal stress — midlobular and centrolobular hepatocytes are progressively recruited to keep up with demand.
In Pi-MZ livers, immunostaining for AAT shows positivity across hepatocytes from adjacent lobules, fading from full periportal staining out toward the midlobular and pericentral zones, where you see characteristic crescent-shaped and double-row patterns. In Pi-ZZ livers (the more severe homozygous form) the staining is more concentrated: dense globules confined mostly to the periportal zone, filling up the cytoplasm. In MZs the polymer accumulation is more widespread but less intense. Under conditions of inflammation or hormonal stimulation the synthesis of both M and Z increases in parallel — but the M is exported and the Z is retained, so the more AAT serum levels rise, the more the liver is also accumulating polymer. This is the paradox that makes inflammatory states particularly costly for an MZ liver.
Liver volume and blood flow also drop with age — typically 20–40% by older adulthood — which is part of why most Alpha-1 MZ problems start showing up in mature adult life rather than in childhood. The practical advice that follows from all of this is the same advice that's good for any liver: avoid alcohol, avoid NSAIDs like ibuprofen which are especially hard on the MZ liver, and avoid unnecessarily high doses of supplements. Routine blood work that includes liver enzymes (ALT, AST, GGT) and ideally a fibroscan or transient elastography every few years gives you an early warning if things are progressing.
Most of the gut effects of Alpha-1 MZ aren't direct hits on the intestine itself — they're downstream of the liver. When liver capacity drops, one of the things the liver does worse is producing and secreting bile acid. Bile acid is what your small intestine uses to emulsify and absorb fats; it's also what keeps the bacterial population in the upper small intestine in check. When bile acid output is impaired, both jobs slip.
The bacterial-control side of that is the main story. Without enough bile acid washing through, bacteria that ordinarily belong further down in the colon can creep upward and colonise the small intestine. This is small intestinal bacterial overgrowth, or SIBO, and it has a long list of symptoms: bloating, flatulence, intermittent diarrhoea or loose stools, brain fog, fatigue, sometimes nausea or unintended weight loss. For an MZ patient, the underlying cause may be at the liver — but the symptoms show up in the gut, and they're often blamed on diet or stress when they're actually a knock-on effect of impaired hepatic bile production.
SIBO matters beyond comfort because it's the entry point to the absorption issues. An overgrown small intestine doesn't absorb micronutrients efficiently — particularly fat-soluble vitamins (A, D, E, K) and B vitamins, with B12 being the most clinically significant. That's the bridge into the neurological section. If you suspect SIBO, breath testing (lactulose or glucose hydrogen/methane) is the standard diagnostic. Treatment is usually a course of a poorly-absorbed antibiotic like rifaximin, sometimes with prokinetics to keep things moving afterwards. Working on the upstream cause — bile acid availability — is harder, but bile acid sequestrant management and dietary modifications can help.
Practical advice for MZs noticing persistent gut symptoms: get bile acid status looked at, ask your gastroenterologist about SIBO testing rather than accepting "irritable bowel" as the final answer, and if vitamin or mineral deficiencies are showing up on bloodwork, treat them as a clue that the absorption side is struggling rather than just supplementing past them.
Neurological problems are among the more serious and most under-diagnosed effects of Alpha-1 MZ. They have an outsized impact on quality of life — fatigue, peripheral tingling and numbness, balance issues, walking difficulties, cognitive fog — and they're often blamed on aging, stress or "just one of those things." For many MZs, however, the neuropathy is not a direct effect of low circulating AAT. It's a second- or third-order consequence: a vitamin B12 absorption problem in the small intestine, downstream of the bile acid and SIBO chain described in the gastrointestinal section. Another inherited disease may also play a role, sometimes in combination.
B12 (cobalamin) is needed to maintain the myelin sheath around peripheral nerves and to support red blood cell production. When absorption fails — whether because of SIBO, inflammation in the gut, gastritis, autoimmune issues affecting intrinsic factor, or any combination of these — B12 levels drop, and over months to years the nerves and the blood start showing it. The classic presentation is symmetric distal sensory neuropathy (the "stocking-glove" pattern), often accompanied by macrocytic anaemia and sometimes by cognitive changes that look superficially like early dementia.
Diagnosis is straightforward but easy to miss: serum B12, plus methylmalonic acid (MMA) and homocysteine, which are more sensitive markers of functional deficiency than the serum B12 level alone. Many people with symptomatic B12 deficiency have a serum value in the "normal" range that's still functionally too low for them. Asking your doctor to run MMA and homocysteine alongside the B12 is worth doing.
Treatment in the absence of an absorption issue is oral B12 supplementation — but in MZ patients with a confirmed absorption problem, oral B12 may not be enough on its own. The standard approach is intramuscular hydroxocobalamin: a loading course of injections (often every other day for two weeks), followed by maintenance injections at intervals that depend on how the symptoms respond. Important caveat: standard B12 dosing protocols don't take liver capacity into account, and B12 is processed and stored in the liver. In an MZ liver with reduced capacity, the storage between maintenance doses may not last as long as the standard interval assumes — so intervals (and doses) should be discussed in light of liver status, not just the textbook schedule. The Facebook page for Alpha-1 and neuropathy is a useful patient community for sharing experiences and dosing strategies.
Within the Alpha-1 MZ patient community, tendon sheath issues and ligament problems come up often enough that they're worth discussing as a pattern rather than as individual coincidences. The mechanism is the same one that drives the lung story: AAT protects elastin and other elastic components from being broken down by serine proteases. When AAT is low, the proteases are less constrained, and any tissue that depends on intact elastic structures pays a small ongoing price.
Tendon sheaths — the protective sleeves around tendons in the hands, wrists, ankles and feet — are particularly visible. MZs report tenosynovitis, trigger finger, plantar fasciitis, and chronic Achilles or wrist tendon pain at rates that anecdotally seem higher than in the general population, although the underlying epidemiological work is still thin. Ligament laxity and slow recovery from minor sprains are also reported. None of this is dramatic, none of it is the headline, but cumulatively it's the kind of thing that grinds people down over years.
There isn't a specific MZ-targeted treatment for connective tissue effects — what helps is the same things that help anyone with tendinopathy: graduated loading rather than rest alone, eccentric exercise, physiotherapy, and avoiding the mechanical patterns that triggered the issue in the first place. Cortisone injections are tempting but should be used sparingly, especially around tendons where they can weaken the tissue further. If you've had multiple unrelated tendon or ligament issues without an obvious mechanical cause, mention the MZ genotype to whoever's treating them — it may change how aggressively they intervene and how patient they are with rehab timelines.
AAT deficiency primarily affects the lungs and the liver, but it can show up in the skin too — most strikingly through a condition called necrotising panniculitis. Panniculitis is an inflammation of the subcutaneous fat layer; in the AAT-deficient form, painful, red or purplish nodules and plaques appear on the trunk, thighs or arms, sometimes ulcerating and discharging an oily fluid. It's rare, and it's most often associated with the more severe ZZ genotype, but it can occur in MZs as well. When it does it usually responds dramatically to AAT augmentation therapy or to dapsone, which is the relevant point: misdiagnosing it as ordinary cellulitis or a soft-tissue infection can lead to courses of antibiotics that don't help, when the underlying cause is an unopposed protease attacking the fat layer.
Beyond panniculitis, the skin's elastic structure depends on elastin, and elastin is one of the proteins that AAT protects from breakdown. The clinical literature on this is still thin, but there are signals that AAT deficiency may contribute to premature skin aging: sagging, loss of firmness, fine wrinkling out of proportion to chronological age. None of this is dangerous, but it's the kind of thing some MZs notice in their forties and fifties and don't have a name for.
A handful of inflammatory skin conditions have also been linked to AAT deficiency in case reports and small series — psoriasis, eczema, vasculitis — but the evidence base is much thinner here, and it would be wrong to claim a settled relationship. If you have an unexplained inflammatory skin condition that isn't responding to standard treatment, it may be worth mentioning your MZ status to your dermatologist, but it shouldn't be the first explanation reached for.
For pregnant MZs, the most clinically important issue is intrahepatic cholestasis of pregnancy — ICP. ICP is a liver disorder that typically develops in the third trimester, marked by intense itching (often starting in the palms and soles, often worse at night), elevated bile acids in the blood, and an increased risk of preterm birth, foetal distress and stillbirth. It usually resolves within days of delivery, and the standard treatment is ursodeoxycholic acid plus careful monitoring and a planned earlier delivery if bile acid levels rise above the threshold.
The MZ link is well established now. The Kosinski 2021 paper in Frontiers in Genetics showed that the Z allele in heterozygotes — i.e. MZs — significantly increases the risk of developing ICP, and in fact the Z allele has emerged as the leading single genetic risk factor for the condition. The mechanism is the same one that drives the rest of the MZ liver story: an MZ liver under hormonal stress (and pregnancy is one of the biggest hormonal stresses a body can experience) ramps up AAT synthesis, but the misfolded Z fraction accumulates inside hepatocytes faster than the liver can clear it. The bile acid output side of liver function gets squeezed, bile acids back up into the maternal bloodstream, and ICP follows.
The practical implications for an MZ planning a pregnancy: tell your obstetrician about the genotype early. If you develop unexplained itching in the second half of pregnancy — especially palms-and-soles itching that's worse at night and not associated with a rash — push for bile acid testing rather than being told it's normal pregnancy itch. The threshold for treatment with ursodeoxycholic acid is well established, and earlier delivery (usually around 36–37 weeks for moderate ICP, 34–36 weeks for severe) reduces the risk of the worst foetal outcomes. ICP Care, an international patient advocacy organisation, is a useful resource for navigating diagnosis and management; one of the foundation's own team members, Dr. Laura Bonebrake, sits on its board.
If you've had ICP in one pregnancy, the recurrence risk in subsequent pregnancies is high — typically 60–70% — so the conversation with your OB next time around can start much earlier. Family members who are also MZ may want to know about the link in advance.
The Alpha-1 MZ Foundation is patient-funded, independent, and entirely free for anyone to use. We do not charge for any of the information on this site, the questionnaires, the newsletters or the webinars. That is by design — and it is only possible because of donations from people who think this work matters.
Donations directly support the four pillars of the foundation's work: awareness and recognition with policymakers and clinicians, global expansion of patient communities and translations, education through newsletters, webinars and explainers, and fundamental research — including biobanks, biomarker work, and underserved areas like intrahepatic cholestasis of pregnancy where mothers and babies are directly affected.
There are 35 million MZ individuals in the world. Far too many of them are unwell without ever being told why — some with liver disease, some with lung issues, some with pregnancy complications, some with autoimmune problems, and many simply feeling unwell without a proper diagnosis. Every contribution, large or small, helps us reach more of them.
Give securely online using any major card, Apple Pay, Google Pay or iDEAL. We also accept bank transfers — just email us. All donations go directly to the foundation's work.
Share your story. Filling in one of our questionnaires takes a few minutes and contributes directly to the foundation's research dataset — the larger that dataset gets, the stronger the case we can make to clinicians and policymakers.
Subscribe and forward. Subscribe to the Substack newsletter and forward issues to anyone in your network who might find them useful — particularly anyone with an unexplained mix of liver, lung, neurological or autoimmune symptoms.
Get tested, then test your family. Alpha-1 is inherited. A diagnosis in one branch of the family tree is a reason for the rest of the family to get tested. The single most useful thing you can do for the people you love is help them find out their genotype before symptoms develop.
Each questionnaire below feeds into our research dataset. Pick the one that fits you. Submissions are stored securely and treated as confidential research data.
Loading…
Loading…
The Alpha-1 MZ Foundation is the data controller for all personal data processed via this site. This page explains, in plain language, what we collect, why, on what legal basis, how long we keep it, who we share it with, and the rights you have. If you want the formal legal text, the full statement is available on request at privacy@alpha1mz.org.
This site sets exactly one cookie: a short-lived session cookie for Foundation administrators. There are no analytics, no third-party tracking, no advertising cookies, no social-media pixels. No consent banner is needed because we do not use any cookies that would require one.
Three kinds of data enter our systems. Questionnaire responses — including health data you voluntarily share — are stored in our database for research purposes, with explicit consent. Story submissions are held as drafts until a Foundation reviewer approves them for publication, with the identity mode you choose (anonymous, initials, first name or full name). Donation records are kept for seven years under Dutch fiscal law. Card payment data is processed by Stripe and never seen by the Foundation.
We use four processors. TransIP (Netherlands) hosts the website and database. Stripe (Ireland / USA) processes donations. Anthropic (USA) translates CMS edits — no personal data is sent to the translation API, only site copy. Substack (USA) delivers the newsletter if you subscribe there. A Data Processing Agreement is in place with each. No data is sold, ever.
You have the right to access your data, correct it, delete it, obtain a portable copy, restrict processing, object to processing, and withdraw consent at any time. To exercise any of these rights, use the request form linked below or email privacy@alpha1mz.org. We respond within one month. You also have the right to file a complaint with the Autoriteit Persoonsgegevens at autoriteitpersoonsgegevens.nl.
For any privacy-related question, email privacy@alpha1mz.org. For general Foundation contact, info@alpha1mz.org.
Version 2026-04-22-v1. This page is a plain-language summary. The full formal privacy statement is available on request and from the Foundation's records. Not legal advice.
Use this form to request access, correction, deletion, a portable copy, or any other action on your personal data. We will respond within one month as required by Article 12(3) GDPR. We may contact you at the email you provide to verify your identity before releasing any personal data.
Your story helps other MZ patients know they are not alone. Submit it here; we review every submission before anything appears on the site, and nothing is published without your explicit consent to the specific way you want to be identified.