For instance, conditions like 3-methylglutaconic aciduria [25], galactose-1-phosphate uridylyltransferase deficiency [94], beta-ketothiolase deficiency [26], Lesch-Nyhan syndrome [39], Leigh syndrome [46], OPA3 deficiency [48], 6-pyruvoyl-tetrahydropterin synthase deficiency [60], multiple carboxylase deficiency [27], and succinic semialdehyde dehydrogenase deficiency [71] may exhibit chorea at an early stage. The gene discussed is OPA3; the disease is Lesch-Nyhan syndrome.