A Novel ELP2 Compound Heterozygous Mutation in a Boy with Severe Intellectual Disability, Spastic Diplegia, Stereotypic Behavior and Review of the Current Literature.

The elongator complex consists of 6 highly conserved subunit proteins and is indispensable for various cellular functions, such as transcription elongation, histone acetylation, and tRNA modification. The elongator complex contains 2 subunits, each of which consists of 3 different proteins (encoded by the ELP1-3 and ELP4-6 genes). According to the OMIM database, ELP2 gene variations have been reported to be associated with autosomal recessive mental retardation type 58. Here, we report a male patient with severe intellectual disability, spastic diplegia, and stereotypic behavior; in addition, we also provide a review of the current literature. Using whole-exome sequencing analysis, we detected a novel compound heterozygous variation in the ELP2 gene. We present this case report to clarify the clinical findings of a very rare neurodevelopmental phenotype and to contribute new information to the current literature on genotype-phenotype correlations.