Journal Article

First case report of Cohen syndrome in the Tunisian population caused by VPS13B mutations

Rejeb, Imen, Elaribi, Yasmina, Benjemaa, Lamia, Hizem, Syrine, Chelly, Jamel, Jilani, Houweyda, Zillahrdt, Julia Lauer, Hila, Lamia

2017

Overview

Background Cohen syndrome is a rare autosomal recessive developmental disorder that comprises variable clinical features counting developmental delay, pigmentary retinopathy, myopia, acquired microcephaly, truncal obesity, joint hypermobility, friendly disposition and intermittent neutropenia. VPS13B (vacuolar protein sorting 13, yeast, homologue of B) gene is the only gene responsible for Cohen Syndrome, causative mutations include nonsense, missense, indel and splice-site variants. The integrity of the Golgi apparatus requires the presence of the peripheral membrane protein VPS13B that have an essential function in intracellular protein transport and vesicle-mediated sorting. Case presentation In this study, we performed whole exome sequencing (WES) in a Tunisian family with two young cases having developmental delay, hypotonia, autism spectrum disorder, ptosis and thick hair and eyebrows. The proposita presented also pigmentory retinopathy. Compound heterozygous mutation in VPS13B gene was detected by WES. This mutation inherited from healthy heterozygous parents, supports an unpredictable clinical diagnosis of Cohen Syndrome. The proband’s phenotype is explained by the presence of compound heterozygous mutations in the VPS13B gene . This finding refined the understanding of genotype-phenotype correlation. Conclusions This is the first report of a Tunisian family with Cohen syndrome mutated in the VPS13B gene.

• Publisher: BioMed Central,BioMed Central Ltd,BMC
• Subject: Biomedical and Life Sciences / Biomedicine / Case Report / Case studies / Child / Child, Preschool / Clinical-Molecular Genetics and Cytogenetics / Cohen syndrome / Compound heterozygous mutation / Cytogenetics / Development and progression / Development Biology / Developmental Disabilities - genetics / Developmental Disabilities - pathology / Exome - genetics / Female / Fingers - abnormalities / Fingers - pathology / Gene Function / Gene mutations / Genetics / Genome, Human / Health aspects / Human Genetics / Humans / Intellectual Disability - genetics / Intellectual Disability - pathology / Life Sciences / Male / Microcephaly - genetics / Microcephaly - pathology / Muscle Hypotonia - genetics / Muscle Hypotonia - pathology / Mutation / Myopia - genetics / Myopia - pathology / Obesity - genetics / Obesity - pathology / Pedigree / Prognosis / Vesicular Transport Proteins - genetics / VPS13B gene