Prise en charge thérapeutique d'une hyperphénylalaniné mie par défaut de synthèse périphérique en tétrahydrobioptérine

Hyperphenylalaninemia is a metabolic disorder characterised by an accumulation of phenylalanine which is toxic for central nervous system. We report the case of young boy, aged 3 years, affected by a BH4-deficient because of biopterin synthase deficiency. At first, when the patient was one month, he was concomitantly treated by tetrahydrobiopterin, levodopa + carbidopa, serotonin and folinic acid without dietary phenylalanine restriction. Only BH4 and folinic acid were continued after one year of follow-up. In conclusion, according to biological parameters, it was demonstrated that the patient was suffering from a peripherical form of the defiency. Diagnosis and therapeutic management were described in the article.