maple syrup urine disease
Findings
No curated finding names maple syrup urine disease yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
An autosomal recessive inherited disorder caused by mutations in the BCKDHA, BCKDHB, DBT, and DLD genes. It is characterized by a deficiency of branched-chain alpha-keto acid dehydrogenase complex, leading to accumulation of metabolites in the body fluids. The name of the disease derives from the sweet odor of the urine in infants, reminiscent of maple syrup. Signs and symptoms usually appear in infancy and include lethargy and developmental delays. If untreated, it may lead to seizures, coma, and death.
Definition from the Mondo Disease Ontology (MONDO:0009563), read 2026-09-29. CC BY 4.0.
Features
13 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Abnormality of the pharynxHPOHP:0000600
- Very frequent (80% to 99% of cases)
- Abnormality of the voiceHPOHP:0001608
- Very frequent (80% to 99% of cases)
- Diminished deep tendon reflexHPOHP:0001315
- Very frequent (80% to 99% of cases)
- Elevated circulating branched-chain amino acid concentrationHPOHP:0008344
- Very frequent (80% to 99% of cases)
- Global developmental delayHPOHP:0001263
- Very frequent (80% to 99% of cases)
- HypotoniaHPOHP:0001252
- Very frequent (80% to 99% of cases)
Show the remaining 1
- Severe intellectual disabilityMondoHP:0010864
Genes
3 genes
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- BCKDHAHGNC:986
- Definitive · Ambry Genetics · Autosomal recessive · 2018
- Definitive · Natera · Autosomal recessive · 2022
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2022
- BCKDHBHGNC:987
- Definitive · Natera · Autosomal recessive · 2022
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2022
- DBTHGNC:2698
- Definitive · ClinGen · Autosomal recessive · 2018
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2022
Where it sits
- Narrower terms (9)
- classic maple syrup urine disease
- intermediate maple syrup urine disease
- intermittent maple syrup urine disease
- maple syrup urine disease type 1A
- maple syrup urine disease type 1B
- maple syrup urine disease type 2
- maple syrup urine disease, mild variant
- pyruvate dehydrogenase E3 deficiency
- thiamine-responsive maple syrup urine disease
Other names
7 names
Resolves to: maple syrup urine disease
- Also called
- BCKD deficiencyBCKDH deficiencybranched chain ketoaciduriabranched-chain 2-ketoacid dehydrogenase deficiencybranched-chain ketoaciduriaKetoacidaemiaMSUD