Mutations in the VPS13B Gene in Iranian Patients with Different Phenotypes of Cohen Syndrome.

Cohen syndrome is a rare autosomal recessive disorder characterized by hypotonia, obesity, developmental delay, mental retardation, and facial, oral, ophthalmic, and limb deformities. Mutations in VPS13B have been found to be responsible for this disorder. In the current report, we have assessed three Iranian families with developmental delay and skeletal deformities. Whole exome sequencing of the affected probands led to identification of the underlying genetic cause in these families. Three mutations were found in VPS13B gene. The detected mutations were c.4608_4609del (p.E1537Rfs7), c.11486dupG (p.L3830Tfs13), and c.10360dupC (p.L3454fs*7). The current study broadens the mutation spectrum of VPS13B gene and demonstrates different phenotypic features from classic Cohen syndrome. Moreover, the provided data can be used in genetic counseling and prenatal diagnosis of Iranian patients.