Are the methylenetetrahydrofolate reductase 1298 and 677 gene polymorphisms related to optic glioma and hamartoma risk in neurofibromatosis type 1 patients? - Hikmet Gülşah Tanyıldız; Şule Yeşil; Ceyhun Bozkurt; Mehmet Onur Çandır; Sibel Akpınar-Tekgündüz; Şule Toprak; Deniz Yüksel; Gürses Şahin (The Turkish Journal of Pediatrics, 2016)