ICD-11 definition : Maple syrup urine disease (MSUD) is a disorder of branched-chain amino acids metabolism.
Four forms are described. The early onset classic form manifests after birth by lethargy,
poor feeding and neurological signs of intoxication. Clinical course without treatment
is characterized by deepening coma with maple syrup odor of urine. Subacute MSUD manifests
later with encephalopathy, mental disability, major hypotonia, opisthotonus and cerebral
atrophy with severe outcome. The intermittent form of MSUD may manifest at any age
and presents with repeated ketoacidotic coma. Thiamine-responsive MSUD is a very rare
form characterized by improvement of the biochemical profile with thiamine therapy.;
Maple syrup urine disease (MSUD) is a disorder of branched-chain amino acids metabolism.
Four forms are described. The early onset classic form manifests after birth by lethargy,
poor feeding and neurological signs of intoxication. Clinical course without treatment
is characterized by deepening coma with maple syrup odor of urine. Subacute MSUD manifests
later with encephalopathy, mental disability, major hypotonia, opisthotonus and cerebral
atrophy with severe outcome. The intermittent form of MSUD may manifest at any age
and presents with repeated ketoacidotic coma. Thiamine-responsive MSUD is a very rare
form characterized by improvement of the biochemical profile with thiamine therapy.