common genetic cause of mental retardation

Scientists have discovered a genetic cause for a neurological developmental disorder that could affect tens of thousands of people worldwide. A paper in the journal Nature Medicine linked genetic changes in a non-coding gene known as RNU4-2 to these disorders, improving clinical diagnosis of affected patients.

A team of researchers, consisting of specialists from Mount Sinai Hospital (USA), the University of Bristol (UK), the University of Leuven (Belgium) and NIHR BioResource of the University of Cambridge, carried out a detailed genetic study using the whole genome. sequencing data. They compared the presence of rare genetic variants in 41,132 non-coding genes in 5,529 cases of mental retardation and in 46,401 controls without the disease.

The study found that mutations in the RNU4-2 gene, a short non-coding DNA sequence, cause neurodevelopmental symptoms that have not previously been associated with a specific genetic disorder. Non-coding genes do not generate proteins, which has made them difficult to study and recognize as causing disease.

This discovery is important because it represents one of the most common genetic causes of neurodevelopmental disorders caused by a single gene, second only to Rett syndrome. Mutations in RNU4-2 are usually spontaneous and not inherited, which provides significant insight into the nature of these disorders.

“We conducted an extensive genetic association analysis to identify rare variants in non-coding genes that may be implicated in neurodevelopmental disorders,” said study lead author Daniel Green. “It is extremely rare to find a single gene responsible for tens of thousands of patients with a rare disease. “Our results remained hidden from researchers for many years due to a number of problems with analysis and sequencing.”