VARIATION AT THE MJD LOCUS IN THE MAJOR PSYCHOSES

Expansion of triplet repeats has been seen to underlie several disorde rs that manifest anticipation. Clinical evidence suggests that anticip ation occurs in the major psychoses. We studied the distribution of re peat sizes at the Machado-Joseph disease (MJD) locus in a group of pat ients with the major psychoses. We did not find any large expansions, though 2 patients had alleles that were two repeats larger than in our controls. The difference in allele sizes was larger in the patient sa mple as compared to the controls, The effect of such large differences might be of functional significance. (C) 1998 Wiley-Liss, Inc.