Other disorders of branched-chain amino-acid metabolism

This code represents a group of rare inherited metabolic disorders affecting the breakdown of branched-chain amino acids (BCAAs) such as valine, leucine, and isoleucine, excluding maple syrup urine disease. These conditions result from deficiencies in specific enzymes involved in BCAA catabolism, leading to the accumulation of toxic metabolites. Clinical manifestations can vary widely depending on the specific enzyme defect and severity, ranging from mild developmental delays to severe neurological dysfunction and metabolic crises.

Use this code for patients diagnosed with a confirmed disorder of branched-chain amino acid metabolism other than maple syrup urine disease. This includes conditions like isovaleric acidemia, propionic acidemia, methylmalonic acidemia, and 3-methylcrotonyl-CoA carboxylase deficiency. Documentation should clearly specify the particular branched-chain organic acidemia or other related metabolic defect identified through biochemical testing (e.g., urine organic acids, plasma amino acids) and/or genetic analysis.

• Ensure the documentation explicitly rules out maple syrup urine disease, as that has a specific code.
• Always look for more specific codes within the E71.1 category if the exact disorder is known and has a dedicated code.
• Code any associated neurological, developmental, or systemic manifestations separately, linking them to the underlying metabolic disorder.