GCH1 and hyperinsulinemic hypoglycemia, familial, 4: These conditions can be a feature of various IMDs, including autosomal dominant or recessive GTP cyclohydrolase-1 deficiency (Dopa-responsive dystonia), glutaryl-CoA dehydrogenase deficiency (Glutaric acidemia type 1), pantothenate kinase 2 deficiency (neurodegeneration with brain iron accumulation type 1), copper-transporting ATPase subunit beta deficiency (Wilson disease), hypoxanthine-guanine phosphoribosyl transferase deficiency (Lesch-Nyhan disease), methylmalonic aciduria, propionic acidemia, and severe pediatric encephalomyopathies (e.g., Leigh syndrome), among others [25].