Biallelic BICD2 variant is a novel candidate for Cohen-like syndrome

Abstract

Heterozygous mutations in Bicaudal D2 Drosophila homolog 2 (BICD2) gene, encodes a vesicle transport protein involved in dynein-mediated movement along microtubules, are responsible for an exceedingly rare autosomal dominant spinal muscular atrophy type 2A which starts in the childhood and predominantly effects lower extremities. Recently, a more severe form, type 2B, has also been described. Here, we present a patient born to a consanguineous union and who suffered from intellectual disability, speech delay, epilepsy, happy facial expression, truncal obesity with tappering fingers, and joint hypermobility. Whole-exome sequencing analysis revealed a rare, homozygous missense mutation (c.731T>C; p.Leu244Pro) in BICD2 gene. This finding presents the first report in the literature for homozygous BICD2 mutations and its association with a Cohen-Like syndrome. Patients presenting with Cohen-Like phenotypes should be further interrogated for mutations in BICD2.