They discovered a genetic mutation that causes mental retardation in tens of thousands of people.

They discovered a genetic mutation that causes mental retardation in tens of thousands of people.freepick

An international team of researchers has discovered a neurodevelopmental disorder caused by mutations in a single gene that affects tens of thousands of people worldwide.a discovery that will improve the diagnosis of these patients.

The work, led by researchers from Icahn School of Medicine at Mount Sinai and published this Friday in natural medicine, This was done in collaboration with the University of Bristol (UK), the University of Leuven (Belgium) and the NIHR BioResource of the University of Cambridge (UK).

Through careful genetic analysis, researchers discovered that mutations in a small non-coding gene called RNU4-2 cause a variety of developmental symptoms. up to this point it had not been associated with another genetic disorder.

The team used whole-genome sequencing data from the UK National Genomic Research Library to compare the burden of rare genetic variants in 41,132 non-coding genes between 5,529 unlinked cases with intellectual disability and 46,401 unlinked controls.

“We conducted a large genetic association analysis to identify rare variants in non-coding genes. this may be a cause of neurodevelopmental disorders,” explains study first author Daniel Green of Icahn-Mount Sinai.

“Today, finding a single gene that carries genetic variants responsible for tens of thousands of patients with a rare disease is extremely unusual. Our discovery eluded researchers for years due to various analytical and sequencing problems,” he comments.

Genetic mutations

More than 99% of the genes known to contain mutations that cause neurodevelopmental disorders encode proteins.

The team hypothesized that non-coding genes, which do not make proteins, may also contain mutations that cause mental retardation.

Neurodevelopmental disorders, which typically appear before the start of elementary school, include developmental disorders that affect personal, social, academic, or occupational functioning.

Specific, mental retardation includes significant limitations in intellectual functioning (eg learning, reasoning, problem solving) and in adaptive behavior (eg social and practical skills).

“The genetic changes we discovered involve a very short gene, only 141 units long, but this gene plays a critical role in a basic biological function of cells called gene splicing, which is present in all animals, plants and fungi,” it details. The study’s lead author is Ernest Turro of Icahn-Mount Sinai.

“Most people with neurodevelopmental disorder They are not given a molecular diagnosis after genetic testing. Thanks to this study, tens of thousands of families will now be able to receive a molecular diagnosis for their affected relatives, ending many diagnostic odysseys,” he adds.

The team now plans to study the molecular mechanisms underlying the syndrome to gain biological information that could one day lead to targeted interventions.