Otopalatodigital syndrome type 2

Otopalatodigital syndrome type 2 is a disorder primarily involving abnormalities in skeletal development. It is a member of a group of related conditions called otopalatodigital spectrum disorders, which also includes otopalatodigital syndrome type 1, frontometaphyseal dysplasia, Melnick-Needles syndrome, and terminal osseous dysplasia. In general, these disorders involve hearing loss caused by malformations in the tiny bones in the ears (ossicles), problems in the development of the roof of the mouth (palate), and skeletal abnormalities involving the fingers or toes (digits). Otopalatodigital syndrome type 2 also tends to cause problems in other areas of the body, such as the brain and heart.

People with otopalatodigital syndrome type 2 have characteristic facial features including wide-set and downward-slanting eyes; prominent brow ridges; a broad, flat nose; and a very small lower jaw and chin (micrognathia). Affected individuals often have abnormalities of the fingers and toes, such as unusual curvature of the fingers (camptodactyly) and shortened or absent thumbs and big toes. People with otopalatodigital syndrome type 2 usually have short stature, abnormally curved (bowed) bones in the arms and legs, and other abnormal or absent bones. Underdeveloped ribs can cause problems with breathing in affected individuals. Some people with this condition have an opening in the roof of the mouth (a cleft palate) or hearing loss.

In addition to skeletal abnormalities, individuals with otopalatodigital syndrome type 2 may have developmental delay, increased fluid in the center of the brain (hydrocephalus), protrusion of the abdominal organs through the navel (omphalocele), heart defects, chest abnormalities, obstruction of the ducts between the kidneys and bladder (ureters), and, in males, opening of the urethra on the underside of the penis (hypospadias).

Males with otopalatodigital syndrome type 2 generally have much more severe signs and symptoms compared to affected females. Males with this condition typically do not survive past infancy because of respiratory failure due to an underdeveloped rib cage.