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Scientists have identified the genetic underpinnings of a disorder associated with intellectual disability, shedding light on a condition that may affect as many as one in 20,000 young individuals.

The disorder, characterized by intellectual disability alongside features such as short stature, small heads, seizures, and low muscle mass, has long puzzled medical experts due to its elusive nature. 

Published in Nature Medicine, the findings of the study conducted by researchers led by Ernest Turro, Ph.D., Associate Professor of Genetics and Genomic Sciences at Icahn Mount Sinai and a Visitor at the University of Cambridge, offer a crucial step forward in understanding and diagnosing the disorder.

Lead investigator Ernest Turro expressed astonishment at the prevalence of the disorder compared to other rare diseases tied to a single gene. Turro emphasized the potential of these findings in aiding doctors in the accurate identification of the disorder, which could significantly impact patient care.

"Most people with a neurodevelopmental disorder do not receive a molecular diagnosis following genetic testing. Thanks to this study, tens of thousands of families will now be able to obtain a molecular diagnosis for their affected family members, bringing many diagnostic odysseys to a close," he said, Science Daily reported.

Dr. Charles Billington, a pediatric geneticist at the University of Minnesota who was not involved in the study, underscored the challenges doctors face in diagnosing such disorders, noting the difficulty in recognizing the subtle signs associated with them.

"So certainly this wasn't something that we necessarily had a name for," he said as per ABC News. "We're learning more about these syndromes that we recognize only once we are seeing the cause."

The study revealed that mutations occurred in a "non-coding" gene, which does not encode instructions for protein synthesis. This marks a departure from the conventional focus on protein-coding genes in genetic studies.

Utilizing "whole-genome" data from approximately 77,000 individuals, including 5,500 with intellectual disability from the British government's 100,000 Genomes Project, the researchers identified rare mutations in the gene RNU4-2 strongly linked to the potential for intellectual disability.

Andrew Mumford, research director of the South West England NHS Genomic Medicine Service and a study co-author, hailed the findings as a significant breakthrough, offering hope for thousands of families seeking answers.

However, Mumford stressed the need for further research to elucidate how the mutation leads to the disorder, highlighting the current lack of treatment options.

"It helps them come to terms with the impact," he said, according to NBC News. "Being able to tell someone, 'Yes, we have found the cause of development disorder in your child' is incredibly powerful."