Oculodentodigital dysplasia (ODDD) is a rare genetic disorder affecting the eyes (oculo-), teeth (dento-), and fingers or toes (digital). Individuals with ODDD may be born with small eyes or other eye abnormalities that cause vision loss, small teeth that have a weak outer layer (enamel), and extra skin (webbing) between the fingers or toes (syndactyly). Other features of the condition include abnormal hair growth (hypotrichosis), brittle nails, small head size (microcephaly), abnormally stiff muscles (spasticity), and hearing loss. Some features of the condition can be noticed right at birth while others are more obvious as a person ages.
ODDD is caused by a mutation (change) in the GJA1 gene. This gene provides the instructions for the body to make a protein called connexin43, which is an important part of the physical connection between cells, called gap junctions. Gap junctions allow for communication between adjacent cells that is necessary for cells to grow and develop. When the GJA1 gene is mutated, the gap junction is not made properly and cells can’t communicate with each other, causing the symptoms associated with ODDD.
ODDD can be inherited in an autosomal dominant or autosomal recessive manner, but most cases are autosomal dominant. If a person has the autosomal dominant form of ODDD, only one mutated copy of the GJA1 gene is enough to cause ODDD. A person with the autosomal recessive form of the condition has mutations in both copies of the GJA1 gene. A diagnosis of ODDD is considered in a person with the physical features of the condition, but genetic testing is used to confirm the diagnosis. Treatment options vary depending on symptoms. If your child has been diagnosed with ODDD, talk with your doctor about the current treatment options. Genetic counselors and support groups are also a good source of information.