Figure 3: Silver stained native polyacrylamide gel showing PCR amplified CAG repeats of normal and expanded SCA1 alleles. The lane M represents 20bp ladder as molecular weight or size marker. Lanes 1, 2, 3, 4 and 9 represent expansion of SCA1 allele of affected individuals III12, III2, II11, III10 and II9, respectively. Lane 5, 6, 7, and 8 represent unaffected individuals III11, IV1, II8 and II10, respectively, in the pedigree. The individuals II8 and II10 are women of the family, who come from outside the family