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.
Martinez et al. (2012) used exome sequencing to uncover a homozygous mutation in the NSUN2 gene in two Lebanese sibs with developmental delay and dysmorphic features. These sibs were born to consanguineous parents living in the UAE. The novel mutation deletes the splice acceptor site of exon 6 leading to mRNA instability and lack of NSUN2 protein in patient cells.