A simple and rapid nonisotopic method for sizing CAG repeats in the SCA1 gene.

Spinocerebellar ataxia type 1 is caused by the expansion of a CAG trinucleotide repeat, located at the 5' end of the gene responsible for the disease (SCA1 gene). We propose a simple and rapid method for SCA1 diagnosis, avoiding both radioactive and Southern blotting analysis. The method allows an accurate allele sizing by visualization of polymerase chain reaction products through a silver nitrate-stained polyacrylamide gel.