Diagnosis and treatment of 6-pyruvoyl-tetrahydropterin synthase deficiency

Commentary on the mutation spectrum of and founder effects affecting the PTS gene in East-Asian populations

“…5 They all follow an autosomal-recessive mode of inheritance and the gene mutations of all five enzymes have been reported. 3 The incidence of BH4 deficiency is at 1 in 1 000 000, except that in Taiwanese (much higher than that in Japanese and in Caucasians). 5,6 Liu et al 7 reported that the BH4-deficient HPA was estimated to make up around 30% of the Chinese population in Taiwan suffering from HPA, which is much higher than in Caucasian populations (1.5-2% of HPA).…”

“…Bartholomé et al 2 reported that the neurological signs in these patients were treatable by the oral administration of the neurotransmitter precursors 3,4-dihydroxyphenylalanine (L-DOPA) and 5-hydroxytryptophan (5-HTP), both of which cross the blood-brain barrier. Shintaku et al 3 recommended that this treatment be started within 2 months of birth to help prevent neurological damage. Therefore, the expression 'BH4 deficiency' should be used rather than the terms 'atypical PKU' or 'malignant hyperphenylalaninemia (HPA)' .…”