Mental Retardation, Autosomal Recessive 5

Alternative Names

  • MRT5
Back to search Result
WHO-ICD-10 version:2010

Mental and behavioural disorders

Mental retardation

OMIM Number

611091

Mode of Inheritance

Autosomal recessive

Gene Map Locus

5p15.31

Description

MRT5 is a neurodevelopmental disorder encompassing, in addition to delayed speech and psychomotor development, a number of dysmorphic features such as microcephaly, long and narrow face, bushy eyebrows with synophrys, hypotelorism, large nose with long columella, short philtrum, and full upper lip. Many affected individuals have short stature, and some have later onset of muscular hypertonia and spasticity.

Diagnosis is made upon observing the aforementioned symptoms. Some patients can benefit from specific programs aimed at people with developmental disabilities to help them learn basic life skills.

Molecular Genetics

MRT5 was mapped to chromosome 5p15, consequently causative mutations in the NSUN2 gene were uncovered. The latter gene encodes a conserved RNA methyltransferase, and this indicates to the role of RNA methylation in higher cognitive functions. So mutations in the NSUN2 gene leading to total lack of the NSUN2 protein or to a truncated version of it cause MRT5. The NSUN2 protein also interacts with the mitotic spindle and plays an important role in cell division. This connection between NSUN2 mutations and MRT5 highlights both the role of cell proliferation genes in normal brain development and link between abnormal cell cycle and microcephaly phenotypes.

Epidemiology in the Arab World

View Map
Subject IDCountrySexFamily HistoryParental ConsanguinityHPO TermsVariantZygosityMode of InheritanceReferenceRemarks
611091.2.1LebanonMaleYesYes Seizures; Intellectual disability; ... NM_017755.6:c.538-1G>CHomozygousAutosomal, RecessiveMartinez et al. 2012 The novel mutation d...
611091.2.2LebanonFemaleYesYes Intellectual disability; Axial hypotoni... NM_017755.6:c.538-1G>CHomozygousAutosomal, RecessiveMartinez et al. 2012
611091.2.3LebanonFemaleYesYes Intellectual disability; Axial hypotoni... NM_017755.6:c.538-1G>CHomozygousAutosomal, RecessiveMartinez et al. 2012
611091.1.1United Arab EmiratesMaleNoYes Developmental delay; Cerebellar atrophy... NM_017755.6:c.1020delHomozygousAutosomal, RecessiveKomara et al. 2015
© CAGS 2021. All rights reserved.