Skip to main content


Fig. 5 | Orphanet Journal of Rare Diseases

Fig. 5

From: Diagnostic and therapeutic recommendations for the treatment of hyperphenylalaninemia in patients 0–4 years of age

Fig. 5

Algorithm of BH4 loading test for children after neonatal period and aged < 4 years. The BH4 loading test must be performed in relation to the genotype (the presence of only one responsive mutation or of one mutation of unknown responsiveness). When the genotype is unknown, the BH4 loading test should be performed, if available. BH4: Tetrahydrobiopterin; Phe: Phenylalanine; PKU: Phenylketonuria

Back to article page