Maple syrup urine disease

Disease Overview

Maple syrup urine disease (MSUD) occurs when the body is unable to breakdown certain parts of proteins. This leads to the build-up of toxic substances that can cause organ and brain damage. There are several forms of MSUD. The most common is the classic or infantile form. Symptoms of the classic form of MSUD start in early infancy and include poor feeding, irritability, extra sleepiness, and muscle spasms. If untreated, respiratory failure (lack of oxygen getting to the blood) may occur. The earwax and urine of infants with MSUD smells like maple syrup. The symptoms of other forms of MSUD start in adolescence or adulthood. MSUD is caused by genetic variants in the BCKDHA, BCKDHB, or DBT genes. It is inherited in an autosomal recessive pattern. Diagnosis of MSUD is based on the symptoms, clinical exam, and blood and urine testing. MSUD is often diagnosed based on the results of a newborn screening test. Treatment includes a special protein restricted diet, supplements, and liver transplantation in some cases.[1818][15946][15947][15948]

Synonyms

• Branched chain ketoaciduria
• Branched-chain alpha-keto acid dehydrogenase deficiency
• BCKD deficiency
• Keto acid decarboxylase deficiency
• MSUD
• BCKDH deficiency
• Branched-chain 2-ketoacid dehydrogenase deficiency
• Branched-chain ketoaciduria