Population Genetics of Wild-Type CAG Repeats in the <i>Machado-Joseph Disease</i> Gene in Portugal

Abstract

The absence of association between the size of the repeats and the representation of MJD demonstrates that prevalence is not an indirect reflection of the frequency of large normal alleles. Globally the results obtained are in accordance with a model that postulates the occurrence of a few mutations on the basis of most of the MJD cases worldwide.