... after childhood illness. Treatment includes a low-protein diet. Propionic acidemia (>1 in 75,000). Defect in processing four amino acids leading to ill-ness in newborns, including brain damage, ... in 100,000). Buildup of argininosuccinic acid and ultimate-ly ammonia, leading to brain swelling, coma, and sometimes death. Treatment consists of a low-protein diet, frequent meals, medica-tions ... amino acid leucine. Can cause coma, brain damage, or death in infancy, or emerge later in childhood after infectious ill-ness. Early diagnosis and treatment with low-protein diet and nutritional...