The discovery of new genes that underlie developmental disorders, with phenotypes such as congenital heart defects, seizures and intellectual disabilities, is reported in Nature this week. Up to half of children with severe developmental disorders remain without a genetic diagnosis. The newly implicated genes increase the proportion of children that can now be diagnosed.
Genetic diagnosis of developmental disorders is challenging because some are too rare to be recognized as a discrete clinical entity, some have highly variable symptoms, and some are difficult to distinguish from other, very similar, disorders. To learn more about the genetic causes of these disorders, Matthew Hurles and colleagues performed a UK-wide study of 1,133 children with severe, undiagnosed developmental disorders, made possible as a result of a collaboration with all 24 regional genetics services of the UK National Health Service and Republic of Ireland. They find 12 new genes that underlie the risk of developing such disorders, and show that they can identify the causative gene for 31% of these patients. This represents a 10% increase in the diagnostic yield, relative to our previous knowledge of genes involved in these disorders.