Involvement of MTHFR and TPMT genes in susceptibility to childhood acute lymphoblastic leukemia (ALL) in Mexicans.

BACKGROUND: Folate metabolism plays an essential role in the processes of DNA synthesis and methylation. Deviations in the folate flux resulting from single-nucleotide polymorphisms in genes encoding folate-dependent enzymes may affect the susceptibility to leukemia. This case-control study aimed to assess associations among MTHFR (C677T, A1298C) and TPMT (*2, *3A) mutations as well as to evaluate the synergistic effects of combined genotypes for both genes. Therefore, these genetic variants may lead to childhood acute lymphoblastic leukemia (ALL) susceptibility, in a Mexican population study. METHODS: DNA samples obtained from 70 children with ALL and 152 age-matched controls (range, 1-15 years) were analyzed by real-time reverse transcription polymerase chain reaction (RT-qPCR) to detect MTHFR C677T and A1298C and TPMT*2 and TPMT*3A genotypes. RESULTS: The frequency of the MTHFR A1298C CC genotype was statistically significant (odds ratio [OR], 6.48; 95% 95% confidence intervals [CI], 1.26-33.2; p=0.025). In addition, the combined 677CC+1298AC genotype exhibited a statistically significant result (OR, 0.23; 95% CI, 0.06-0.82; p=0.023). No significant results were obtained from the MTHFR (C677T CT, C677T TT) or TPMT (*2, *3A) genotypes. More importantly, no association between the synergistic effects of either gene (MTHFR and/or TPMT) and susceptibility to ALL was found. CONCLUSIONS: The MTHFR A1298C CC genotype was associated with an increased risk of developing childhood ALL. However, a decreased risk to ALL with the combination of MTHFR 677CC+1298AC genotypes was found.

Influence of CYP1A1*2C on high triglyceride levels in female Mexican indigenous Tarahumaras.

BACKGROUND AND AIMS: High triglyceride levels are closely related to cardiovascular disease. Its development lays on age, diet, physical activity, ethnicity and genetic factors. Among the last, the CYP1A1*2C allele has an influence on the metabolism of cholesterol and other fatty acids. We undertook this study to determine the frequency of CYP1A1*2C and its association with triglyceride levels in Mexican indigenous Tarahumaras and Tepehuanos. METHODS: Anthropometric and biochemical data were recorded. Genotyping of CYP1A1*2C by RT-PCR was done in 110 Tepehuano, 69 Tarahumara and 64 Mestizo. RESULTS: Significant differences in age, waist diameter, BMI, creatinine, glucose, cholesterol, triglycerides, HDL and VLDL measurements were found between Tarahumaras and Tepehuanos (p <0.05). Additionally, Tarahumara women showed the highest values of waist diameter, BMI and triglycerides (p <0.05). It was found that Tarahumaras showed a significant association between high triglyceride levels and CYP1A1*2C allele (OR = 2.57; 95% CI 1.12-5.88, p = 0.024) under a recessive inheritance model. However, the Tepehuano group showed a significant protective association between normal triglyceride levels and CYP1A1*2C polymorphism (OR = 0.28; 95% CI 0.10-0.80, p = 0.015) following a dominant inheritance model. The same pattern was observed after analysis with females of both ethnicities. CONCLUSION: A significant association between CYP1A1*2C and high triglyceride levels in Amerindian Tarahumaras from Chihuahua has been found; this allele was significantly associated with normal triglyceride levels in Tepehuanos from Durango, Mexico. Further studies are needed to elucidate the genetic role of CYP1A1 in cardiovascular disease susceptibility.