[Progressive convulsive encephalopathy: considering a abnormality of biopterin metabolism]. / Encéphalopathie progressive convulsivante: penser aux anomalies du métabolisme des bioptérines.

BACKGROUND: Symptomatic forms of hyperphenylalaninemia are rare in France since neonatal screening began. CASE REPORT: A child born in Algeria from consanguinous parents was referred at 2 years of age for a severe epileptic encephalopathy with hypotonia. Amino acid chromatography revealed hyperphenylalaninemia due to a dihydropteridine reductase deficiency. Dietary restriction of phenylalanine and oral administration of amine precursors, L-dopa and 5-hydroxytryptophan had poor efficiency on epilepsy and psychomotor delay. CONCLUSION: Diagnosis of hyperphenylalaninemia must be evoked in any children with progressive encephalopathy born in country where neonatal screening is not performed.