Molecular analysis of spinocerebellar ataxia trinucleotide repeat behavior in normal individuals of a Brazilian population.

There is a current lack of molecular studies analyzing the behavior of trinucleotide repeat expansions causative of Late Onset Spinocerebellar Ataxias in the Brazilian population. Therefore, this manuscript analyses normal families, as well as one hundred normal individuals of the Espirito Santo State to determine the trinucleotide repeat behavior and the allelic frequencies found in this population. The analysis of normal families demonstrated that, instead of being always stably transmitted over generations, expansions can occur between two generations of unaffected individuals, possibly contributing for the appearance of the ataxic phenotype.