Mental Retardation, Autosomal Recessive 37

A number sign (#) is used with this entry because of evidence that autosomal recessive mental retardation-37 (MRT37) is caused by homozygous mutation in the ANK3 gene (600465) on chromosome 10q21. One such family has been reported.

Clinical Features

Iqbal et al. (2013) reported 3 sibs, born of consanguineous Pakistani parents, with moderate intellectual disability (IQ less than 50). The patients were 25, 22, and 18 years of age at the time of the report. All had delayed global development with speech delay, hypotonia, spasticity, and a sleep disorder. All had severe behavioral abnormalities, including aggression, hyperactivity, and grinding of the teeth. One had seizures. They did not have dysmorphic features. CT scans of 2 patients were unremarkable.

Inheritance

The transmission pattern in the family with MRT37 reported by Iqbal et al. (2013) was consistent with autosomal recessive inheritance.

Molecular Genetics

In 3 Pakistani sibs, born of consanguineous parents, with MRT37 and behavioral abnormalities, Iqbal et al. (2013) identified a homozygous frameshift mutation in the ANK3 gene (600465.0001). The mutation, which was found by homozygosity mapping and whole-exome sequencing and confirmed by Sanger sequencing, segregated with the disorder in the family.