New Huntington's disease Dx simplifies testing approach

Huntington's disease patients may be far better served by a new diagnostic that uses a form of polymerase chain reaction (PCR) technology, researchers in Utah have found. Equally significant, the diagnostic could give quicker results and eliminate the need for additional testing because of inaccuracies.

Scientists from the University of Utah's ARUP Laboratories and the school's Institute for Clinical and Experimental Pathology, and others, participated in the study. The Journal of Molecular Diagnostics highlights the details.

PCR involves growing a few copies of a piece of DNA into thousands or more copies, so researchers can perform diagnostic tests on a particular DNA sequence. For the study, the team looked at 246 samples using chimeric, or triplet repeat primed PCR (TP PCR) methodology. Scientists felt that the method would be beneficial for Huntington's, in part because TP PCR can rapidly and cheaply identify and quantify the key indicator for the disease: abnormal extended repeats of three nucleotides known as CAG. This is important, because a patient's risk for Huntington's disease spikes along with the number of CAG repeats.

The test results were promising, with TP PCR correctly sizing 240 of 246 samples. Out of 146 samples known to have Huntington's disease (greater than 39 CAG repeats), 140 could be correctly identified with other diagnostic methods. And the TP PCR method even worked with samples for which other diagnostic tests didn't function as successfully, the researchers explain. What's more, the new testing method could identify normal samples more easily, eliminating the need for additional diagnostic work to counter any false negatives.

As always, more work needs to be done here. But early and accurate detection of Huntington's will enable drug developers to concoct treatments that may slow the disease's progression at an earlier point or even reverse symptoms. A more robust diagnostic could open all kinds of potential doors to treat the deadly condition.

- read the release