[Trial of folic acid treatment in fragile X syndrome].

Forty-two patients with the fragile-X syndrome have been treated with oral folic acid, 0.5 mg/kg/d. An improvement of the behavior was observed in the majority of the cases, and evolution of the IQ showed a favorable tendency at the border of statistical significance. On the contrary, the addition to the treatment regime of methionine or of carnitine (carriers of methyl radicals) had unfavorable effects. In view of the few preliminary convergent observation recorded in literature, a continued trial of folic acid treatment seems justified. Simultaneously, however, research is indicated on monocarbon metabolism, probably affected in these patients.