亚甲基四氢叶酸还原酶基因单核苷酸多态性与儿童急性淋巴细胞白血病的相关性

Relationship between genetic polymorphism of methylenetetrahydrfolate reductase and the risk of childhood acute lymphocytic leukemia

目的探讨亚甲基四氢叶酸还原酶（MTHFR）基因单核甘酸多态性与儿童急性淋巴细胞白血病（ALL）发病风险的关系。方法分别收集45例ALL患儿（ALL组）及45名健康儿童（对照组）外周血各2ml，提取基因组DNA，应用聚合酶链反应一限制性片段长度多态性（PCR—RFLP）法，检测MTHFRC677T和A1298C基因型，比较不同基因型对儿童ALL发病风险的影响。采用Logistic回归模型计算比值比（OR）和95％可信区间（95％CI）。结果对照组MTHFR677CC、CT和TT基因型分布频率分别为31．1％（14／45）、51．1％（23／45）和17．7％（8／45），ALL组3种基因型分布频率分别为51．1％（23／45）、40．0％（18／45）和8．9％（4／45），两者比较差异有统计学意义（X2=7．48，P=0．04）；MTHFR677T等位基因在ALL组中的检出率为48．8％（22／45），在对照组中的检出率为69．9％（31／45）；T等位基因携带者发生ALIJ的风险是CC基因型的0．4倍（95％CI 0．21～0．83）。对照组MTHFR1298AA、AC和CC基因型分布频率分别为57．8％、40．0％和2．2％，ALL组3种基因型分布频率分别为18．8％、44．4％和6．8％，两者比较差异无统计学意义（X2=11．23，P=0．23）；MTHFR1298C等位基因在ALL组中的检出率为42-2％（19／45），在对照组中的检出率为51．1％（23／45）；C等位基因的存在并不会提高儿童发生ALL的风险（OR=1．3，95％C10．21～0．83）。结论MTHFR677T等位基因的存在会显著降低儿童发生ALL的风险，而MTHFR1298各基因型与儿童ALL的发生均无明显相关性。

Objective To investigate the relationship between genetic polymorphism of methylenetetrahydrofolate reductase （MTHFR） and the risk of childhood acute lymphocytic leukemia （ALL）. Methods 45 patients with ALL and a cohort of 45 matched healthy children were included, and DNA was extracted from their peripheral blood. PCR-RFLP was used to determine the genotypes of MTHFR C677T and At298C. The adjusted odds tatio （OR） and 95 % confidence interwal （C/） were calculated using unconditional logistic regression model. Results The frequency of MTHFR 677 CC, CT and TF genetypes were 31.1% （14/45）, 51.1% （23/45） and 17.7 % （8/45） in controls and 51.1% （23/45）, 40.0 % （18/45） and 8.9 % （4/45） in ALL, respectively （X2 = 7.48, P = 0.04）. The frequency of MTHFR 677 T allele were 69.9 % （31/45） in controls and 48.8 % （22/45） in ALL. The MTHFR 677 T allele had an decreased risk in ALL compared with CC genety]ae （OR = 0.4, 95 % CI 0.21-0.83）. The frequency of MTHFR 1298 AA, AC and CC genetypes were 57.8 %, 40.0 % and 2.2 % in controls and 18.8 %, 44.4 % and 6.8 % in ALL respectively （X2 = 11.23, P= 0.23）. The frequency of MTHFR 1298 C allele were 51.1% （23/45） in controls and 42.2 % （19/45） in ALL. No significant association between the MTHFR 1298 polymorphism and the risk of ALL （OR = 1.3, 95 % CI 0.21-0.83）. Conclusion MTHFR 677 polymorphism could significantly decrease the risk of developing childhood ALL, whereas MTHFR 1298 don＂ t significantly affect the risk of ALL.