Novel mutation in the gene for intellectual disability: A case report and literature review.

MED23 deficiency causes the autosomal recessive Intellectual Disability (ID). Here we report an Iranian case with nonsyndromic ID presenting with developmental delay, microcephaly, hypotonia, severe ID, speech delay, and spasticity, who was homozygous for the novel MED23 c.670C>G variant. These results expand the clinical and mutation spectrum of MED23 deficiency.