IllnessMaple syrup urine disease, differential diagnosis

NGS +

In maple syrup disease, certain amino acids are not metabolized correctly. The distinctive sweet smell of the urine of affected infants is characteristic. Symptoms include vomiting, lethargy, abnormal movements and developmental delays. If left untreated, maple syrup urine disease can lead to seizures, coma and death. The disease is often classified by the pattern of symptoms. The most common, severe and classic type starts soon after birth. Variants occur later in infancy or childhood and are usually milder, but still cause developmental delay and other health problems if not treated properly. Mutations in the BCKDHA, BCKDHB and DBT genes cause the disease. The encoded proteins break down the amino acids leucine, isoleucine and valine, which are found especially in protein-rich foods such as milk, meat and eggs. Since high amounts of the breakdown products are harmful to the brain and other organs, their accumulation leads to the serious health problems. This disease is inherited in an autosomal recessive manner. In typical cases, the molecular diagnostic yield is almost complete.

Reference: https://www.ncbi.nlm.nih.gov/books/NBK1319/

• Alias: Alpha-Ketosäuredecarboxylase-Mangel
• Alias: BCKD deficiency
• Alias: BCKD-Mangel
• Alias: BCKDH-Mangel
• Alias: Branched-chain 2-ketoacid dehydrogenase deficiency
• Alias: Branched-chain alpha-keto acid dehydrogenase deficiency
• Alias: Branched-chain ketoaciduria
• Alias: Ketoacidemia
• Alias: Verzweigtkettenketoazidurie
• Allelic: Pulmonary hypertension, neonatal, susceptibility to (CPS1)
• Alpha-methylacetoacetic aciduria (ACAT1)
• Argininemia (ARG1)
• Argininosuccinic aciduria (ASL)
• Carbamoylphosphate synthetase I deficiency (CPS1)
• Citrullinemia (ASS1)
• Citrullinemia, adult-onset type II (SLC25A13)
• Citrullinemia, type II, neonatal-onset (SLC25A13)
• Dihydrolipoamide dehydrogenase deficiency (DLD)
• Galactosemia (GALT)
• Glycine encephalopathy (AMT, GCSH, GLDC)
• Gyrate atrophy of choroid + retina with/-out ornithinemia (OAT)
• Homocystinuria, cblD type, variant 1 (MMADHC)
• Hyperammonemia due to carbonic anhydrase VA deficiency (CA5A)
• Hyperinsulinism-hyperammonemia syndrome (GLUD1)
• Hyperornithinemia-hyperammonemia-homocitrullinemia syndrome (SLC25A15)
• Isovaleric acidemia (IVD)
• Lysinuric protein intolerance (SLC7A7)
• Maple syrup urine disease, type II (DBT)
• Maple syrup urine disease, type Ia (BCKDHA)
• Maple syrup urine disease, type Ib (BCKDHB)
• Methylmalonic aciduria + homocystinuria, cblD type (MMADHC)
• Methylmalonic aciduria, cblD type, variant 2 (MMADHC)
• Methylmalonic aciduria, mut(0) type (MMUT)
• Methylmalonic aciduria, vitamin B12-responsive, cblA type (MMAA)
• Methylmalonic aciduria, vitamin B12-responsive, cblB type (MMAB)
• Methylmalonyl-CoA epimerase deficiency (MCEE)
• N-acetylglutamate synthase deficiency (NAGS)
• Ornithine transcarbamylase deficiency (OTC)
• Propionicacidemia (PCCA, PCCB)
• Tyrosinemia, type I (FAH)