USAResearch and clinical trials
Single-dose gene therapy tested in 9 children with GM1 gangliosidosis type II
In the USA, 9 children with type II GM1 gangliosidosis were given a single dose of gene therapy into a vein.
Peer-reviewed publicationGM1
Lysosomal storage diseases
GM1 gangliosidosis
An inherited lysosomal storage disease. Fat-like substances build up in the nervous system.
Not part of the panel of Türkiye's National Newborn Screening Programme (heel-prick test). Source
This page is translated from the Turkish original.
This disease is followed through the “Lysosomal storage diseases” group.
Understanding the disease
This section has not yet been reviewed by a physician. It summarises patient information from sources such as MedlinePlus, Orphanet and the NHS in plain language. The disease can differ from person to person; talk to your doctor about diagnosis and treatment.
What happens in this disease?
An enzyme called beta-galactosidase does not work well enough in the body. This enzyme breaks down a fatty substance called GM1 ganglioside. The substance builds up in cells, mostly in the brain, and damages nerve cells. The type that begins in infancy is the most severe and often ends life in early childhood.
Which symptoms can occur?
There are three types, depending on the age when the disease begins. The early-onset types are more severe and progress faster.
- In the infantile type, muscle weakness and loss of skills already gained before 6 months
- Exaggerated startle response to loud sounds (in the infantile type)
- Seizures
- Large liver and spleen, bone differences (in the infantile type)
- Vision loss; a cherry-red spot at the back of the eye (in the infantile type)
- Coarse facial features and weakness of the heart muscle (in some babies)
- Developmental regression in the later-onset types
- In the adult type, involuntary muscle contractions (dystonia) and spine problems
How is it diagnosed?
The doctor suspects the disease from the symptoms and the examination. Some initial tests may be done on blood and urine. The diagnosis is confirmed by measuring the enzyme level in the blood or with a genetic test.
Treatment and care
Care is mostly aimed at easing symptoms and giving support. Some new methods are being researched for the later-onset types. The doctor who follows the disease decides which treatment is suitable.
For the family: inheritance and genetic counselling
The disease is passed on through recessive inheritance. The child receives one changed gene from the mother and one from the father. The mother and father are often healthy carriers. Genetic counselling is recommended for brothers and sisters and for future pregnancies.
Source: MedlinePlus Genetics — GM1 gangliosidosis · Orphanet — GM1 gangliosidosis
Key facts
- How common is it?
- Birth prevalence: 1-9 per 1 000 000 (Europe)
- How is it inherited?
- Autosomal recessive
- When does it usually start?
- Childhood
- Gene(s) involved
- GLB1
- Reliable sources
- MedlinePlus (for families) · Orphanet · GeneReviews (for doctors)
These facts are taken from Orphanet and MedlinePlus records (last checked: October 7, 2026). Frequency values are approximate ranges.
You are not alone: patient associations in Türkiye
Non-profit patient and family organizations in Türkiye working on this disease or disease group. Links are for information; Doktorclub is not affiliated with these organizations and does not endorse them.
- Mukopolisakkaridoz ve Benzeri Lizozomal Depo Hastalıkları Derneği · For the disease group · İstanbul
For all rare diseases: Nadir Hastalıklar Federasyonu
Links checked on October 8, 2026.
Support and help
- In an emergency in Türkiye, call 112.
- For psychological and social support, the ALO 183 Social Support Line (24/7, free from within Türkiye): alo183.aile.gov.tr
- For carers: Looking after yourself as a caregiver
- Preparing for a doctor visit · Collect your questions and symptom notes on one page, then print it and take it with you.
Doktorclub does not diagnose, recommend treatments or refer you to hospitals or doctors. These pages are meant to help you talk with your doctor.
News about GM1
TürkiyeResearch and clinical trials
Gene therapy trials for GM1 gangliosidosis and OTC deficiency at Gazi Hospital
Two gene therapy clinical trials are being carried out at Gazi University.
News reportGM1
Clinical trials (ClinicalTrials.gov)
A clinical trial is a regulated study that tests whether a new treatment is safe and whether it works, in patients who volunteer. Most trials look for a certain age, genetic change and health condition. Taking part is voluntary.
This list is not a treatment recommendation. Treatments tested in phase 1–3 trials are investigational (experimental): their efficacy and safety have not yet been proven and they are not approved treatments. Taking part depends on each trial’s criteria and a physician’s assessment; the first step is to talk to the doctor who manages your care.
Questions you can ask your doctor
- Could this trial be suitable for us?
- If we take part, how would current treatment and check-ups be affected?
- Where does the trial take place, and how are travel and accommodation handled?
- What happens if we want to leave the trial?
ClinicalTrials.gov lists 4 active interventional studies for this disease. 1 is recruiting now; 3 have sites in Türkiye. Last checked: October 7, 2026.
Selected records (studies with a site in Türkiye first):
- A Study to Evaluate the Safety and Efficacy of Oral Nizubaglustat (AZ-3102) in Late-infantile and Juvenile Forms of Niemann-Pick Type C Disease, GM1 Gangliosidosis or GM2 Gangliosidosis
Late stage: the effect is being compared in a large group · Phase 3 · investigational (experimental)RecruitingSite in TürkiyeNCT07054515
- A Study to Evaluate the Safety and Efficacy of Oral Nizubaglustat (AZ-3102) in Late-infantile and Juvenile Forms of GM1 Gangliosidosis or GM2 Gangliosidosis
Late stage: the effect is being compared in a large group · Phase 3 · investigational (experimental)Active, not recruitingSite in TürkiyeNCT07082543
- Study of Safety, Tolerability and Efficacy of PBGM01 in Pediatric Participants With GM1 Gangliosidosis
Middle stage: the effect is being tested in a small group · Phase 1 / Phase 2 · investigational (experimental)Active, not recruitingSite in TürkiyeNCT04713475
- Prenatal Intravenous Gene Transfer With an AAV9 Vector Expressing Human Beta-galactosidase in Type I and Type II GM1 Gangliosidosis Clinical Trial
Early stage: safety and dose are being tested · Phase 1 · investigational (experimental)Not yet recruitingNCT07479953
See all studies on ClinicalTrials.gov · Joining clinical trials
Lysosomal storage diseases: other news
InternationalResearch and clinical trials
In Hunter syndrome, siblings who started enzyme therapy in infancy did better
Records of 19 sibling pairs with Hunter syndrome were compared.
Peer-reviewed publicationMPS II
USANew treatments and approvals
Rebisufligene etisparvovec receives FDA approval as first treatment for Sanfilippo type A
The FDA has approved rebisufligene etisparvovec for children with Sanfilippo syndrome type A (MPS IIIA).
Official drug approvalMPS IIIA
ChinaResearch and clinical trials
Gene therapy tested in 6 children with infantile-onset Pompe disease
In China, 6 children with infantile-onset Pompe disease were given a single dose of gene therapy.
Peer-reviewed publicationPompe
Medical codes (for talking with your doctor and finding sources)
These codes identify the disease in international classifications and databases. They can help when you talk with your doctor or look for reliable sources.
Orphanet code: ORPHA:354
No separate ICD-11 code; WHO classifies this disease under: 5C56.00 (Gangliosidosis)
Codes checked against WHO ICD-11 and Orphanet on October 6, 2026.
This page provides general information and does not replace diagnosis or treatment. Talk to your doctor about symptoms, diagnosis and treatment.