New childhood disease genes found

A pair of studies published in the journal Nature Genetics unveil gene faults lying behind two rare but debilitating childhood diseases. In the first, researchers at Duke University Medical Centre in the US found the gene mutation responsible for alternating hemiplegia of childhood, or AHC  - a condition that causes paralysis of alternate sides of the body, as well as seizures and learning difficulties.

The condition isn't hereditary, so the scientists had to scour the genomes of just seven patients with AHC, comparing them with their parents until they found a gene fault common to all seven. They then went on to show that the mutation, in a gene called ATP1A3, was also present in over three-quarters of AHC patients around the world. While it's a long way from a cure, the scientists hope their finding will increase awareness of the disease and help doctors to make an accurate diagnosis.

The second gene to be tracked down lies behind Leber congenital amaurosis, or LCA - a rare form of blindness that sets in during infancy. After nearly a decade of hunting, the team at the Ocular Genomics Institute in Massachusetts led by Eric Pierce found that faults in a gene called NMNAT1 could cause the disease, bringing the total number of identified LCA mutations to 18.

Unlike other previously identified LCA gene faults, which are in genes involved in light sensing, NMNAT1 helps cells to make energy. They hope that this new discovery could pave the way for interventions to slow or even completely prevent the onset of blindness in these children.