Association of vitamin D receptor gene FokI polymorphism and susceptibility to CAP in Egyptian children: a multicenter study Heba Abouzeid, NourEldin M. Abdelaal, Mohammed A. Abdou, Amira A. A. Mosabah, Mervat T. Zakaria, Mohammed M. Soliman, Ashraf M. Sherif, Mohammed E. Hamed, Attia A. Soliman, Maha A. Noah, Atef M. Khalil, Mohamed S. Hegab, Alsayed Abdel-Aziz, Shaimaa S. A. Elashkar, Rehab M. Nabil, Adel M. Abdou, Ghada M. Al-Akad & Hany A. A. Elbasyouni Collaborative paper, not derived from thesis, Published in: Pediatric Research volume 84, pages 639–644 (2018) Background Community-acquired pneumonia (CAP) is the leading cause of child deaths around the world. Recently, the vitamin D receptor (VDR) gene has emerged as a susceptibility gene for CAP. Objectives To evaluate the association of the VDR gene FokI polymorphism with susceptibility to CAP in Egyptian children. Methods This was a multicenter case-control study of 300 patients diagnosed with CAP, and 300 well-matched healthy control children. The VDR Fok I (rs2228570) polymorphism was genotyped by PCR-restriction fragment length polymorphism (RFLP), meanwhile serum 25-hydroxy vitamin D (25D) level was assessed using ELISA method. Results : The frequencies of the VDR FF genotype and F allele were more common in patients with CAP than in our control group (OR = 3.6; (95% CI: 1.9–6.7) for the FF genotype; P = 0.001) and (OR: 1.8; (95% CI: 1.4–2.3) for the F allele; P = 0.01). Patients carrying the VDR FF genotype had lower serum (25D) level (mean;14.8 ± 3.6 ng/ml) than Ff genotype (20.6 ± 4.5 ng/ml) and the ff genotype (24.5 ± 3.7 ng/ml); P < 0.01.) Conclusion The VDR gene Fok I (rs2228570) polymorphism confers susceptibility to CAP in Egyptian children.