Branched-chain organic acidurias digital illustration

Branched-chain organic acidurias Save


ICD-10 code: E71.11

Chapter: Endocrine, nutritional and metabolic diseases

Branched-chain organic acidurias: Understanding the rare metabolic disorder

Branched-chain organic acidurias (BCOAs) are a group of rare metabolic disorders that affect the way the body processes certain amino acids. BCOAs are caused by a deficiency in one of the enzymes responsible for breaking down these amino acids, leading to the buildup of toxic organic acids in the blood and urine.

The three types of BCOAs are:

  1. Maple syrup urine disease (MSUD)
  2. Isovaleric acidemia (IVA)
  3. Methylmalonic acidemia (MMA)

MSUD is the most common type of BCOA, affecting approximately 1 in 185,000 newborns in the United States. IVA and MMA are rarer, affecting about 1 in 250,000 and 1 in 50,000 newborns, respectively.

BCOAs are inherited in an autosomal recessive manner, which means that a child must inherit two copies of the mutated gene - one from each parent - to develop the disorder. If both parents are carriers of the mutated gene, there is a 25% chance that their child will inherit two copies and develop the disorder.

Common symptoms of BCOAs include:

  • Poor feeding and vomiting
  • Lethargy and weakness
  • Developmental delays
  • Seizures
  • Coma

Early diagnosis and treatment are crucial for managing BCOAs. Treatment typically involves a specialized diet low in the amino acids that the body cannot break down, as well as supplements and medications to manage symptoms and prevent complications.

Overall, while BCOAs are rare, it is important for healthcare providers to be aware of the disorder and to consider it as a possible diagnosis in infants who present with symptoms such as poor feeding, vomiting, and developmental delays.