20 June 2011
ByAppeared in BioNews 612
US scientists have reported possibly the first example of using one person's genetic sequence to refine a diagnosis and provide personalised medical treatment. Whole-genome sequencing (WGS) helped pinpoint defects in the DNA of 14-year-old fraternal twins Noah and Alexis Beery that cause their rare neurological condition, dopamine-responsive dystonia (DRD). The research offers a glimpse into how individual WGS could one day be used to provide personalised medical care, Reuters reports.
DRD is known to be caused by mutations in three genes. Using WGS, researchers and physicians at Texas' Baylor Genome Sequencing Center and the Texas Children's Hospital found the twins didn't have mutations in two genes commonly mutated in DRD. They pinned down the twin's genetic mutations to a third gene, SPR, which plays a critical role in serotonin production. Adding a serotonin-inducing supplement to the twins' medication dramatically improved their symptoms.
Dr Matthew Bainbridge from the Baylor Genome Sequencing Center, who led the study, told Reuters: 'If you saw them today, you'd say there was nothing wrong with them'. He added that, with the cost of sequencing currently halving every six months: 'It's our hope that in two years or maybe even a year whole genome sequencing will be more widely available'.
Retta Beery, the twins' mother, said they have been able to resume normal activities, including sport: 'Now, because of the sequencing, Alexis started on this new amino acid and she started back in track in March'. She added: 'She's been winning races'.
Professor Richard Gibbs, director of the Baylor Center, was encouraged by the research, telling the Houston Chronicle that it was 'one more brick in the wall' to understand the human genome and how it interacts with human health.
The symptoms of DRD are similar to that of Parkinson's Disease and include slow movement, tremors and balance difficulties. The findings are published in the current issue of Science Translational Medicine.