Homozygous 2p11.2 deletion supports the implication of ELMOD3 in hearing loss and reveals the potential association of CAPG with ASD/ID etiology

Autism spectrum disorder ( ASD) is a set of neurodevelopmental conditions characterized by early-onset difficulties in social communication and unusually restricted, repetitive behavior and interests. Parental consanguinitymay lead to higher risk of ASDand to more severe clinical presentations in the offspring. Studies of ASDfamilies with high inbreedingenable the identification of inherited variants of this disorder particularly those with an autosomal recessive pattern of inheritance. In our study, using copy number variants (CNV) analysis, we identified a rare homozygous deletion in 2p11.2 region that affects ELMOD3, CAPG, and SH2D6 genes in a boy with ASD, intellectual disability(ID), and hearing impairment (HI). This deletion may reveal a new contiguous deletion syndrome in which ELMOD3, known to be implicated in autosomal recessive deafness underlies the HI of the proband and CAPG, member of actin regulatory proteins involved in cytoskeletal dynamic, an important function for brain development and activity, underlies the ASD/ID phenotype. A possible contribution of SH2D6 gene, as a part of a chimeric gene, to the clinical presentation of the patient is discussed. Our result supports the implication of ELMOD3 in hearing loss and highlights the potential clinical relevance of 2p11.2 deletion in autism and/or intellectual disability.