Nonsyndromic cleft lip and palate in Philippines and MTHFRC677T polymorphism

INTRODUCTION: Cleft lip and palate is a frequently occurring congenital malformation with one in every 500 to 700 births worldwide. Approximately 70% of all clefts are known as nonsyndromic clefts (NCLP)involving both genetic and environmental factors in their etiology. Several genes identified in the etiology of NCLP (RFC1, MTHFR, MSX1, TGFß3) are being studied at the Pacific Craniofacial Genetics Laboratory (PCFL). Pacific has been involved with Rotaplast for the last eight years giving an opportunity to residents, faculty and students to participate in the treatment of CLP during cleft medical missions to developing countries. The authors were fortunate to view the magnitude of this problem during several missions. OBJECTIVE: The goal of our pilot study was to analyze whether an association between MTHFRC677T polymorphism and NCLP exists in the population of Cebu City.

MATERIAL AND METHODS: Blood specimens of 107 cases (patients affected with NCLP) and 41 controls for this study were collected during Rotaplast cleft medical missions to Cebu City, Philippines in 2003 and 2005. MTHFRC677T genotypes were established at the PCGL using polyacrylamide gel electrophoresis.

RESULTS: Proportions of genotypes were 81.13% CC, 16.98% CT, 1.89% TT in cases and 82.93% CC, 17.7% CT, and no TT in controls. The C allele frequency was 0.896 for cases and 0.915 for controls, while the T allele frequency was 0.104 for cases and 0.085 for controls. The differences w between cases and controls were not statistically significant.

CONCLUSIONS: No definitive conclusion about a role of T allele of the MTHFR in etiology of NCLP in Cebu City can be drawn, because our study, our control group is very small. It seems that frequency of mutated T allele of the MTHFRC677T polymorphism is very low in Cebu City population.

ACKNOWLEDGEMENTS: The fieldwork for this study was supported by Rotaplast International