TürkiyeResearch and clinical trials
Simple test tried to measure heart and diabetes risk in 14 children with Bardet-Biedl syndrome in Istanbul
At Istanbul Faculty of Medicine, 14 children were studied.
Peer-reviewed publicationBardet-Biedl
Genetic syndromes and other conditions
Bardet-Biedl syndrome (BBS)
An inherited disease that affects many organs. Vision loss that starts with night blindness, weight gain and extra fingers or toes are common.
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 “Genetic syndromes and other conditions” 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?
The disease disturbs the work of tiny projections on cells called cilia. Cilia play a role in sight, smell and communication between cells. This is why the eyes, kidneys, hormones and weight balance are affected. The symptoms and course differ greatly from person to person.
Which symptoms can occur?
Not everyone has all the symptoms.
- Vision that starts with trouble seeing at night and narrows over time (in most)
- Excessive weight gain beginning in the first years (common)
- Extra fingers or toes (common)
- Learning difficulties and intellectual disability
- Kidney problems (in many people)
- Differences in the genitals and low sex hormones
- Delay in speaking and walking
- Loss of the sense of smell (sometimes)
How is it diagnosed?
The diagnosis is considered from the symptoms and examination. An eye doctor examines the retina with an ERG; this test measures how the retina responds to light. A genetic test can help confirm the diagnosis.
Treatment and care
Care is aimed at the symptoms, and many specialists work together. A nutrition plan and regular physical activity are important for weight control. There is an approved treatment specifically for excess weight caused by this disease. Extra fingers or toes and some organ differences can be corrected with surgery. Low hormone levels can be supported with hormone treatment. In severe kidney disease, a kidney transplant may be needed. The doctor who follows the disease decides which treatment is suitable.
For the family: inheritance and genetic counselling
Bardet-Biedl syndrome is usually passed on through recessive inheritance. Two changed genes are needed to have the disease; one comes from the mother and one from the father. For a carrier couple, the chance of an affected child in each pregnancy is 1 in 4. In marriages between relatives, the chance of two carriers coming together may be higher. Genetic counselling guides the family.
Source: MedlinePlus Genetics: Bardet-Biedl syndrome · NORD: Bardet-Biedl Syndrome · Orphanet: Bardet-Biedl syndrome (ORPHA:110)
Key facts
- How is it inherited?
- Autosomal recessive · Oligogenic (a few genes together)
- When does it usually start?
- Before birth, Childhood, Infancy, Newborn period
- Gene(s) involved
- BBS1, BBS10, BBS2, BBS4, BBS5, BBS7
- Reliable sources
- MedlinePlus (for families) · Orphanet
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.
We could not find a patient association specific to this disease.
For all rare diseases: Nadir Hastalıklar Federasyonu
Guides related to this disease
- Rare disease at school · Telling the school, medicines and emergency plan, inclusion and BEP, support education room, absences, LGS/YKS arrangements, peer bullying.
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 Bardet-Biedl
TürkiyeResearch and clinical trials
Türkiye's largest Bardet-Biedl series: a genetic cause found in all 25 patients
In Istanbul, 25 patients were tested with a multigene panel.
Peer-reviewed publicationBardet-Biedl
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 3 active interventional studies for this disease. 3 are recruiting now; none has a site in Türkiye. Last checked: October 7, 2026.
Selected records (studies with a site in Türkiye first):
- First-in-Human, Dose Escalation Trial of AXV-101 in BBS1-Related Retinal Degeneration
Early stage: safety and dose are being tested · Early phase 1 · investigational (experimental)RecruitingNCT07269665
- Real-World Effects of MC4R Agonist Therapy in BBS and Severe Genetic Obesity
Phase 4 · follow-up study of an approved drugRecruitingNCT07674290
- COhort for Bardet-Bield Syndrome and Alström Syndrome for Translational Research Monocentric Interventional Study
Non-drug study (device, procedure, care, etc.)RecruitingNCT04461444
See all studies on ClinicalTrials.gov · Joining clinical trials
Genetic syndromes and other conditions: other news
TürkiyeResearch and clinical trials
Brain MRI findings in more than half of children with Noonan syndrome in Ankara
Ankara University reviewed the brain MRIs of children with Noonan syndrome.
Peer-reviewed publicationNoonan
TürkiyeResearch and clinical trials
Sotos syndrome study from 14 centers in Türkiye: 48 children studied
In Türkiye, 14 centers jointly studied children with Sotos syndrome and the similar Malan syndrome.
Peer-reviewed publicationSotos
FranceResearch and clinical trials
In Noonan syndrome, the cholesterol drug simvastatin did not benefit growth in a phase 3 trial
In France, simvastatin was compared with placebo in children with Noonan syndrome.
Peer-reviewed publicationNoonan
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:110
No separate ICD-11 code; WHO classifies this disease under: 5A61.0
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.