1.
Coşkun T, Karagöz T, Kalkanoğlu S, et al. Guanosine triphosphate cyclohydrolase I deficiency: a rare cause of hyperphenylalaninemia. Turk J Pediatr. 1999;41(2):231-237. Accessed April 15, 2026. https://turkjpediatr.org/article/view/3225