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Updated: Aug 25, 2026

Cerebellar Regional Dissection for Molecular Analysis
Published on: December 5, 2020
Genetic polymorphism at spinocerebellar ataxia 1 and 2 loci in Brazil
Stenio F P Duarte1, Raquel S Gestinari, Mário Campos Junior
1Human Genetics Service, Department of Cell Biology and Genetics, State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazi.
Abstract:
Dynamic mutation involves the expansion of a tandem arrayed DNA sequence that is polymorphic in the population. This mechanism is associated with neurological/neuromuscular disorders and the pathology depends on the extension of the repeated tract, with a specific threshold for each disease. We made a PCR-based characterization of allelic polymorphism of SCA1 and SCA2 loci in a sample of 200 pairs of chromosomes in a population in Rio de Janeiro and found 23 different alleles at the SCA1 locus, varying from 10 to 39 CAG repeats (mean 27.7 +/- 3.3, mode 28) and 10 different alleles ranging from 19 to 29 CAG (mean 22.1 +/- 1.0, mode 22) at the SCA2 locus. The level of heterozygosis was 53% (SCA1) and 8% (SCA2).
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