Long term outcome of organic acidurias: survey of 105 French cases (1967-1983).

The French experience in the long term follow-up of 105 cases of organic aciduria (45 maple syrup urine disease, 12 isovaleric acidaemia, 19 propionic acidaemia, 24 methylmalonic aciduria and some rare allied disorders) is reported. Main conclusions drawn from this survey are the poor overall prognosis and the slow improvement in the outcome of such disorders over the last 15 years. In MSUD, while early diagnosis and early management remain a basic requirement, intellectual development did not improve as much as expected. In propionic and methylmalonic acidaemia modern treatment does not prevent a fatal outcome in the classical neonatal forms. It should be also emphasized that in the rare cases where a coenzyme deficiency has been demonstrated, vitamin therapy is very often ineffective in vivo.