Maple Syrup Urine Disease Gene Panel

Autosomal dominant

1/185,000 ^{1, 2, 3}

Major clinical symptoms for MSUD include the following ¹: 

• Maple syrup odor of earwax
• Poor feeding, irritability, lethargy
• Focal dystonia
• Stereotypic behaviours
• Coma and central respiratory failure

Diagnosis of maple syrup urine disease is based on the presence of characteristic findings such as:

• Presence of allo-isoleucine in plasma is diagnostic
• Elevated BCAAs in plasma,
• Elevated BCKAs in urine, and/or

the presence of pathogenic variants in one of the associated genes: BCKDHA, BCKDHB, DBT, DLD

Treatment for MSUD includes specific nutrition and dietary measures¹:

• Restriction of leucine and intake of only BCAA-free foods
• Supplementation with isoleucine and valine
• Correction of metabolic decompensation by providing glucose, insulin, free amino acids, isoleucine, and valine for protein synthesis
• Hemodialysis/hemofiltration to remove accumulated BCAA.
• Liver transplantation is an effective therapy for classic MSUD
• Thiamine supplementation

• Urea cycle defects (NAGS deficiency, ornithine transcarbamylase deficiency, citrullinemia, arginase deficiency and others)
• Organic acidemias (propionic academia, isovaleric academia, methylmalonic academia with homocystinuria, multiple carboxylase deficiency)
• Beta-ketothiolase deficiency
• Glycine encephalopathy (non-ketotic hyperglycinemia)

To confirm/establish the diagnosis, CENTOGENE offers the following tests:

• MSUD NGS Panel which includes sequencing of the BCKDHA, BCKDHB, DBT and DLD genes
• MSUD NGS Panel + CNV which includes sequencing and additionally detection of large deletions and duplications from the NGS data

• Individuals with a positive family history of maple syrup urine disease
• Individuals with most common symptoms of MSUD (regardless of family history)

Confirmation of a clinical diagnosis through genetic testing of MSUD can allow for genetic counseling and may direct medical management.