Lysosomal storage diseases
An inherited storage disease. Certain sugar chains build up in the cells. Learning difficulties, hearing loss and frequent infections may occur.
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.
A change in the MAN2B1 gene disrupts the enzyme alpha-mannosidase. This enzyme breaks down sugar chains attached to proteins. The chains that are not broken down build up in the cells and damage them. There are different forms, from mild to severe.
Symptoms vary greatly from person to person. Mild forms progress slowly.
The enzyme alpha-mannosidase is measured in white blood cells. Some sugar chains may be found to be high in the urine. The diagnosis is confirmed with a genetic test for the MAN2B1 gene.
There is an approved enzyme replacement therapy for symptoms outside the nervous system. Infections are treated early. Hearing aids and ear tubes help hearing. Physiotherapy, speech therapy and special education are important. A bone marrow transplant is an option being researched. The doctor who follows the disease decides which treatment is suitable.
The disease is passed on through recessive inheritance. The mother and father are usually healthy carriers. For a couple who are both carriers, the chance of having an affected child is 1 in 4 in each pregnancy. Diseases of this kind may be more common in marriages between relatives. Genetic counselling guides the family.
Source: MedlinePlus Genetics: Alpha-mannosidosis · NORD: Alpha-Mannosidosis
These facts are taken from Orphanet and MedlinePlus records (last checked: October 7, 2026). Frequency values are approximate ranges.
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.
For all rare diseases: Nadir Hastalıklar Federasyonu
Links checked on October 8, 2026.
Doktorclub does not diagnose, recommend treatments or refer you to hospitals or doctors. These pages are meant to help you talk with your doctor.
GlobalResearch and clinical trials
In an international study that included Ankara, 21 children who had a stem cell transplant for alpha-mannosidosis were studied.
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.
Questions you can ask your doctor
ClinicalTrials.gov lists 2 active interventional studies for this disease. 1 is recruiting now; none has a site in Türkiye. Last checked: October 7, 2026.
Selected records (studies with a site in Türkiye first):
Early stage: safety and dose are being tested · Phase 1 · investigational (experimental)RecruitingNCT02254863
Middle stage: the effect is being tested in a small group · Phase 2 · investigational (experimental)Active, not recruitingNCT02171104
See all studies on ClinicalTrials.gov · Joining clinical trials
InternationalResearch and clinical trials
Records of 19 sibling pairs with Hunter syndrome were compared.
USANew treatments and approvals
The FDA has approved rebisufligene etisparvovec for children with Sanfilippo syndrome type A (MPS IIIA).
ChinaResearch and clinical trials
In China, 6 children with infantile-onset Pompe disease were given a single dose of gene therapy.
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:61
No separate ICD-11 code; WHO classifies this disease under: 5C56.21
Codes checked against WHO ICD-11 and Orphanet on October 7, 2026.
This page provides general information and does not replace diagnosis or treatment. Talk to your doctor about symptoms, diagnosis and treatment.