LEP and autosomal dominant cerebellar ataxia: This possibility is further strengthened by our expected finding of positive correlation between leptin and both BMI and fat mass in the non-SCD controls, the observation that the pattern of reduction in plasma leptin levels seen in the two case sub-groups correlated with pattern of reduction in BMI and fat mass by gender and the persistence of lower leptin level in the unsteady SCA sub group after correction for fat mass.