GALT and Lesch-Nyhan syndrome: These patients had the following inborn errors of metabolism: 3-methylglutaconic aciduria, galactose-1-phosphate uridylyltransferase deficiency, beta-ketothiolase deficiency, Lesch-Nyhan syndrome, Leigh syndrome, OPA3 deficiency, 6-pyruvoyl-tetrahydropterin synthase deficiency, multiple carboxylase deficiency and succinic semialdehyde dehydrogenase deficiency.