TRINUCLEOTIDE (CAG) REPEAT LENGTH IS POSITIVELY CORRELATED WITH THE DEGREE OF DNA FRAGMENTATION IN HUNTINGTONS-DISEASE STRIATUM

Recent studies using DNA fragmentation assays suggest a role for apopt osis in cell death in Huntington's disease. In this study, we investig ated the relationship between the degree of DNA fragmentation and the number of trinucleotide (CAG) repeats of the Huntington's disease gene in striatal tissue from Huntington's disease brains. We used frozen s triatal tissue from 27 post mortem Huntington's disease brains (graded 0-4 on the Vonsattel classification, post mortem delay ranging from 4 to 41 h), plus control sections which were age, sex and post mortem d elay matched from neurologically normal and Alzheimer's diseased stria tal tissue. Our results show a significant positive correlation betwee n the number of CAG repeats in the Huntington's disease gene and the d egree of DNA fragmentation in Huntington's disease striatum. These res ults suggest that expanded CAG repeats in the Huntington's disease gen e may lead to neuronal degeneration in Huntington's disease through an apoptotic mechanism. (C) 1998 IBRO. Published by Elsevier Science Ltd .