Novel KIAA1033/WASHC4 mutations in three patients with syndromic intellectual disability and a review of the literature.

In 2011, KIAA1033/WASHC4 was associated with autosomal recessive intellectual disability (ARID) in a large consanguineous family comprising seven affected individuals with moderate ID and short stature. Since then, no other cases of KIAA1033 variants have been reported. Here we describe three additional patients (from two unrelated families) with syndromic ID due to compound heterozygous KIAA1033 variants ascertained by exome sequencing (ES). Two sisters, aged 4 and 5.5 years, had a stop-gain and a missense variants, each inherited from one parent (p.(Gln442*) and p.(Asp1048Gly)). Both had learning disabilities, macrocephaly, dysmorphic features, skeletal anomalies, and subependymal heterot…