NEUROLOGICAL OUTCOME OF METHYLMALONIC ACIDEMIA

Objective-To assess the long term outcome of patients with methylmalon ic acidaemia in a cross sectional study. Patients-All 35 patients with methylmalonic acidaemia seen at Great Ormond Street Hospital for Chil dren in London, UK between 1970 and 1996 were studied. They were divid ed into cobalamin responsive (n = 6) and non-responsive (n = 29), and early and late onset groups. Results-There was a significant differenc e between cobalamin responsive and non-responsive groups in severity, survival, and incidence of neurological sequelae. Cobalamin responsive patients had mild disease, irrespective of age at presentation, their neurological complications were less severe, and they are all alive. The cobalamin non-responsive group comprised 19 early and nine late on set patients. The early onset patients had more severe disease at pres entation and 14 have died; all late onset patients are alive. There wa s no significant difference in abnormal neurological signs, although e arly onset patients had a significantly reduced full scale intelligenc e quotient and poor cognitive outcome. In both groups, abnormal neurol ogical signs continue to increase with age. Conclusions-Cobalamin resp onsive patients have a better long term outcome. The outcome in the no n-responsive patients, particularly the early onset group, remains poo r and alternative treatments should therefore be considered early in t his group.