A novel mutation in a common pathogenic gene (SETD5) associated with intellectual disability: A case report

Intellectual disability (ID) is a non-specific phenotype present in a genetically heterogeneous group of disorders. The genetic cause of ID remains elusive in the majority of patients due to this extreme heterogeneity. Whole exome sequencing technology has been applied to identify pathogenic gene variants responsible for ID. The present report described a 1.7-year-old female patient who had severe ID with the specific features of delayed motor development, language disorders and abnormal facial features. Exome analysis identified a novel pathogenic variant of the SETD5 gene [c.2025_2026delAG (p.Gly676Valfs*2)]. The variant was a frameshift mutation, causing termination of the protein in advance. These findings indicated that this mutation of the SETD5 gene may be a genetic cause for ID. The present study aimed to provide a meaningful exploration of ID and the identification of clinical core genetic pedigrees.