Background: Genetic or genomic mutation is a major cause of intellectual disability (ID). Albeit great progress in detection of genetic syndromes associated with Intellectual Disability (ID), research is still needed. We describe the phenotype associated with a candidate mutation inEMC10(previously known asC19Orf63) (c.287delG/p.Gly96Alafs). EMC10encodes a member of endoplasmic reticulum (ER)-membrane protein complex (EMC), an evolutionarily conserved complex proposed to have multiple roles in ER-associated degradation, ER-mitochondria tethering, and proper assembly of multi-pass transmembrane proteins.

Method: Candidatemutation inEMC10, identified by a combination of autozygosity mapping and exome sequencing, was found in five children with ID from a large IsraeliBedouin Muslim family. The functioning of five individuals (aged 7-18) homozygous for EMC10 candidate mutation was compared to normative data as well as to that of age-matched relatives (siblings/cousins), sharing similar familial and demographic characteristics. Their neuropsychological, motor, psychological functioning, and daily functioning were assessed.

Results: Performance of all participants with EMC10 candidate mutation was lower than the normal range. Moreover, their intellectual, cognitive, motor, emotional, and behavioral functioning was lower than that of their matched relatives. A discrepancy between verbal and non-verbal abilities was found, with lower verbal abilities compared to visuospatial ability.

Conclusion: We describe a novel genetic ID disorder, associated with a homozygous truncating mutation of EMC10, and its’ neuropsychological functioning.