A team of French and Swiss researchers has developed a chip to facilitate the diagnosis of Huntington's disease. The micro device measures the length of regions of DNA connected to the disease in less than 5 minutes.
Scientists have also tested it on samples of patients with type 1 myotonic dystrophy, with excellent results. Genetic diseases such as Huntington are caused by the presence of trinucleotide repetitions in a gene. In the case of Huntington's disease, there are too many CAG trinucleotide repeats. The particular nature of the genetic defect extends the timing of the diagnosis by traditional sequencing.
Researchers from the Universities of Toulouse and Lausanne tested a chip called μLAS, which measures the trinucleotides associated with Huntington. The chip acts like a funnel, dividing the DNA into smaller fragments. At this point a fluorescent dye is used and a marker that divides the fragments by weight. All this facilitates the measurement of the different sections of DNA, determining if there are abnormal areas.
The new system has proven effective in diagnosing 5 cases of Huntington's and 3 of dystrophy. The diagnoses took all 5 minutes or less, while covering the whole range of possible expansions in both diseases. Furthermore, the test proved to be very sensitive, so that the researchers did not have to expand the samples.