Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 43 6 2014 06 15 821 7 Arezoo Jahanbin 1. Dept. of Orthodontics, School of Dentistry, Mashhad University of Medical Sciences , Mashhad, Iran. Nadia Hasanzadeh 2. Dental Material Research Center, School of Dentistry, Mashhad University of Medical Sciences , Mashhad, Iran. Faraneh Abdolhoseinpour 3. Mashhad University of Medical Sciences , Mashhad, Iran. Ariane Sadr-Nabavi 4. Dept. of Medical Genetics, School of Medicine, Mashhad University of Medical Sciences , Mashhad, Iran. Mohammad-Ali Raisolsadat 5. Dr. Sheikh Hospital, Mashhad University of Medical Sciences , Mashhad, Iran. Khosro Shamsian 6. Jahade Daneshgahi of Mashhad , Mashhad, Iran. Farnaz Mohajertehran 7. Dental Research Center, Mashhad University of Medical Sciences , Mashhad, Iran. Hamidreza Kianifar 8. Dept. of Pediatric Gastroenterology, Ghaem Medical Center, Mashhad University of Medical Sciences , Mashhad, Iran. 2015 10 15 Non-syndromic cleft lip with or without cleft palate (nsCL/P) is one of the most common congenital abnormalities of the orofacial region with a multifactorial etiology. The present study aimed to investigate the association of two common polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene (c.677C>T and c.1298A>C) with the occurrence of nsCL/P in an Iranian population.Forty-five nsCL/P patients, 43 mothers of patients, and 101 unrelated controls participated in the present study. Analysis of c.677C>T and c.1298A>C polymorphisms in MTHFR gene was conducted using polymerase chain reaction and restriction enzyme digestions.There was no statistical difference in genotype and allele frequencies for c.677C>T variants between patients or their mothers and the control group. However, differences in the frequencies of alleles and genotypes of c.1298A>C polymorphism were statistically significant between patients and control group (P=0.01 for alleles and P=0.005 for genotypes). The odds ratios (OR) for the CC versus AA homozygotes were 6.1 (95% CI 1.8-20.5) and 4.2 (95% CI 1.1-15.4), in patients and mothers, respectively.We found no association between genetic polymorphism of MTHFR c.677C>T and the risk of nsCL/P in the population studied. Yet the results suggested that c.1298A>C polymorphism of MTHFR gene may be a risk factor for the occurrence of nsCL/P in the Iranian population. https://ijph.tums.ac.ir/index.php/ijph/article/view/4054 https://ijph.tums.ac.ir/index.php/ijph/article/download/4054/3713