|Other names||Dwarfism-Onychodysplasia, Fifth Digit Syndrome, Mental Retardation with Hypoplastic 5th Fingernails and Toenails, Short Stature-Onychodysplasia|
|Coffin–Siris syndrome is inherited in an autosomal dominant manner|
Coffin–Siris Syndrome is a rare genetic disorder that causes developmental delays and absent fifth finger and toe nails. There had been 31 reported cases by 1991. The number of occurrences since then has grown and is now reported to be around 80.
- mild to severe intellectual disability, also called "developmental disability"
- short fifth digits with hypoplastic or absent nails
- low birth weight
- feeding difficulties upon birth
- frequent respiratory infections during infancy
- joint laxity
- delayed bone age
- coarse facial features, including wide nose, wide mouth, and thick eyebrows and lashes
Autosomal dominant inheritance is the most likely, usually by de novo mutation.
The diagnosis is generally based on the presence of major and at least one minor clinical sign and can be confirmed by molecular genetic testing of the causative genes. Recent studies revealed that fifth finger nail/distal phalanx hypoplasia or aplasia is not a mandatory finding.
There is no known cure or standard for treatment. Treatment is based on symptoms and may include physical, occupational and speech therapy and educational services as well.