Scientists have conducted the largest and most diverse study to date on how recessive genetic changes contribute to developmental disorders. They found that most undiagnosed cases that are due to recessive causes are linked to genes we already know about.

Researchers from the Wellcome Sanger Institute and their collaborators at GeneDx analysed genetic data from nearly 30,000 families affected by developmental disorders – six times more families with greater diversity in ancestral backgrounds compared to previous work.

While discovering several genes that were previously not linked to these conditions, researchers found that known genes explain over 80 per cent of cases caused by recessive genetic variants. This is a significant increase from previous estimates. The study also revealed the contribution of recessive genetic variants to developmental disorders varies significantly across the ethnic groups studied.

The findings, published today in the journal Nature Genetics, shed new light on the genetic basis of developmental disorders, and highlight the importance of considering a person's genetic background in diagnosis and research.