In contrast, in spite of the moderate prevalence of FVL mutation (2.97–5.5%) among normal population of Iran49,50 a high prevalence of FVL mutation (14.3%) among Iranian SCA patients9 has been found with a significant association between this mutation and SCA with odds ratios (OR) of 6.5 (95% confidence intervals [CI] 1.19–35.33, p = 0.03). This evidence concerns the gene F5 and autosomal dominant cerebellar ataxia.