The status of SCA1, MJD/SCA3, FRDA, DRPLA and MD triplet containing genes in patients with Huntington disease and healthy controls

A number of human hereditary neuromuscular and neurodegenerative disorders are caused by the expansion of trinucleotide repeats within certain genes. Here we report the results of the analysis of five trinucleotide repeats co ntaining genes (SCAI, MJD/SCA3, DRPLA, FRDA and MD) in HD patients and in a group of healthy controls. Allelic frequency distributions for SCAI and FR DA genes were shifted toward larger alleles in the group of unrelated HD pa tients, compared to healthy controls. This linkage disequilibrium suggests a possible existance of a common mechanism of trinucleotide repeats expansi on in these loci.