A rare, genetic disorder of pyrimidine metabolism characterized by increased serum beta-alanine levels and severe phenotype including hypotonia, malaise, seizures, respiratory distress, lethargy and encephalopahty. Urinary excretion of beta-alanine, beta-amino-isobutyric acid, taurine, and gamma-amino-butyric acid is also elevated. There have been no further descriptions in the literature since 1994.