Mutations in the VPS13B gene result in Cohen Syndrome. VPS13B is a transmembrane protein encoded by the VPS13B gene located at chromosomal position 8q22.2. VPS13B plays an important role in the development and the function of the eye, hematological system, and central nervous system. The mechanism by which abnormalities in this protein lead to the phenotype of Cohen Syndrome is currently unknown, but VPS13B is thought to play a role in sorting proteins within the cell. VPS13B co-localizes with the protein GM130 and is integral for maintaining the structure and function of the Golgi complex.
Mutations in VPS13B can be identified using next generation sequencing or targeted variant analysis. Deletions have also been observed in patients with Cohen Syndrome, and deletion and duplication testing is available.