KITLG and autosomal dominant cerebellar ataxia: Succinate dehydrogenase (SDH) activity was highest in the SCA group (11.30 ± 0.60 nmol/min/mg), followed by the SCF group (9.12 ± 2.12 nmol/min/mg) and the control group (6.23 ± 0.85 nmol/min/mg), with the SCY group showing the lowest activity (3.22 ± 0.65 nmol/min/mg).