- Biedl-Bardet Syndrome
- Progressive vision loss due to deterioration of the retina. Typically, this begins in mid-childhood with problems with night vision and is followed by the development of blind spots in the peripheral vision. These blind spots become bigger with time and eventually merge to produce tunnel vision. Most individuals also develop blurred central vision and become legally blind by adolescence or early adulthood (more than 90% of the cases).
- Extra finger next to the fifth finger (postaxial polydactyly) in about 69% of the cases.
- Kidney problems (polycystic kidneys) in about 53% -82% of the cases.
- Obesity that develops around 2-3 years of age (72% of the cases).
- Abnormalities of the genitalia and infertility (most in men) due to failure in the production of sex hormones in the body (hypogonadism) (59% of the cases) and infertility.
- Learning disorders.
Bardet-Biedl syndrome may also be associated with other manifestations, including diabetes, high blood pressure, heart defects and bowel disease (Hirschsprung disease).  For this reason, it is recommended that patients are followed by a team of several specialists, such as pediatricians, cardiologists, gastroenterologists, nephrologists, ophthalmologists, etc.
Other signs and symptoms that may be present are:
- Neurological problems resulting in gait and coordination impairment
- Speech and language problems
- Behavioral disorders
- Distinctive facial appearance
- Dental abnormalities.
The Human Phenotype Ontology provides the following list of signs and symptoms for Bardet-Biedl syndrome. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms.
The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature.
The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined.
Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
- Bardet-Biedl syndrome. Genetics Home Reference. September 2013; http://ghr.nlm.nih.gov/condition/bardet-biedl-syndrome.
- Bardet-Biedl syndrome. Orphanet. 2008; http://www.orpha.net/consor/cgi-bin/Disease_Search.php?lng=EN&data_id=3244.
- Waters AM & Beales PL. Bardet-Biedl Syndrome. GeneReviews. April 23, 2015; http://www.ncbi.nlm.nih.gov/books/NBK1363/.