Cohen Syndrome is an autosomal recessive condition, caused by two mutations in the VPS13B gene. This gene provides instructions for making the protein VPS13B. VPS13B is believed to help sort proteins in the cell, and provides support for the structure and function of the Golgi apparatus, which is a packaging system within the cell that that combines simple molecules to make complex molecules. VPS13B plays an important role in the development of the eye, hematological system, and central nervous system.
At conception, each sibling of an affected individual has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier. Carrier testing for at-risk relatives and prenatal testing for pregnancies at increased risk are possible if the VPS13B mutations present in the family have been identified. Genetic testing is available for individuals suspected of being affected with Cohen Syndrome.