Inborn errors of amino acid metabolism phenylketonuria and disorders of biopterin metabolism

Disorders of amino acid metabolism lead to accumulations of amino acids that lead to toxicity to the developing central nervous system. Others are neuropharmacologic toxins. Phenylketonuria and disorders of biopterin metabolism cause hyperphenylalaninemic toxicity. Tyrosinemia leads to hepatic and renal disease. Organic acidemias such as propionic and methylmalonic lead to ketoacidosis. Glutaric aciduria type I leads to neurodegeneration, and macrocephaly. Maple Syrup urine disease leads to neonatal opisthotonus and seizures.