NSUN2 Gene Mental Retardation, Autosomal Recessive Type 5 Genetic Test in UAE

The NSUN2 gene encodes an RNA methyltransferase essential for proper neurodevelopment. Biallelic loss-of-function mutations disrupt RNA methylation, leading to impaired neuronal protein synthesis and synaptic function. This manifests as autosomal recessive intellectual disability type 5, characterized by global developmental delay, significant speech impairment, and cognitive deficits presenting in early childhood. Clinical interpretation must integrate pedigree analysis and segregation studies for accurate variant classification.

A peripheral whole blood sample, extracted DNA, or a single blood spot on an FTA card is collected by a DHA-licensed phlebotomist during a scheduled home visit. The specimen is transported under temperature-controlled cold-chain conditions to our CAP-accredited laboratory. High-coverage next-generation sequencing is performed to detect single nucleotide variants, insertions, deletions, and splice-site alterations across the entire NSUN2 coding region and flanking intronic sequences.

The assay achieves 99.9% diagnostic sensitivity under ISO 9001:2015 quality standards. Accuracy depends on sample integrity, high-molecular-weight DNA extraction quality, and rigorous variant interpretation by board-certified clinical geneticists. Inconclusive results may require additional family member testing, functional studies, or complementary biochemical assays to resolve variants of uncertain significance.

A positive result confirms a molecular diagnosis of autosomal recessive intellectual disability type 5, enabling accurate recurrence risk counseling for family planning and eligibility for targeted early intervention programs. A negative result does not exclude all genetic causes of intellectual disability; additional genetic tests such as whole-exome sequencing or chromosomal microarray may be considered based on clinical presentation and family history.