Whole Exome Sequencing Identifies a Novel Homozygous Duplication Mutation in the VPS13B Gene in an Indian Family with Cohen Syndrome.

Cohen syndrome (CS) is an autosomal recessive congenital disorder, characterized by hypotonia, intellectual disability, developmental delay, microcephaly, progressive retinopathy, neutropenia, truncal obesity, joint laxity, characteristic facial, ophthalmic, oral and appendage abnormalities, and an over friendly behavior. It has been linked to mutations in the VPS13B gene. The main purpose of this study was to determine the genetic cause of CS in an Indian family. Whole exome sequencing (WES) was used to identify the genetic cause of CS in the family. The WES analysis identified a homozygous novel duplication mutation c.5272dupG in the VPS13B gene, leading to formation of a truncating protein. The present study will be advantageous in genetic diagnosis and genetic counseling in CS, and increases the mutational spectrum of this gene.