Objectives: To study the distribution characteristics of methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism in children with primary hypertension, and to explore the association between MTHFR C677T gene polymorphism and H-type hypertension in children.
Methods: A total of 121 children with primary hypertension who were hospitalized in the department of cardiovascular medicine from January to July 2021, newly diagnosed, and untreated were retrospectively selected as the subjects. The children were divided into three groups: CC genotype (19 children), CT genotype (51 children), and TT genotype (51 children). According to the serum homocysteine (Hcy) level, they were divided two groups: H-type hypertension (47 children) and simple hypertension (74 children). The medical data were compared between the groups. The association between MTHFR C677T gene polymorphism and H-type hypertension was evaluated.
Results: The mutation frequency of T allele in children with primary hypertension was significantly higher than that in healthy adults in Beijing and Chinese Han adults (P<0.001). The serum Hcy level in the TT genotype group was significantly higher than that in the CC and CT genotype groups (P<0.001). The serum Hcy level in the H-type hypertension group was significantly higher than that in the simple hypertension group (P<0.001), and MTHFR C677T was mostly TT genotype, which was associated with the risk of H-type hypertension (OR=12.71, P<0.001). There was no significant difference in the incidence rate of target organ damage between the H-type hypertension and simple hypertension groups (P>0.05). However, multiple organ involvement was observed in the H-type hypertension group at diagnosis, accounting for 11% (5/47).
Conclusions: The mutation rate of MTHFR C677T T allele in children with primary hypertension is high and associated with the serum Hcy level. TT genotype is an independent risk factor for H-type hypertension in children, and it may be related to the severity of early target organ damage.
目的: 分析原发性高血压儿童亚甲基四氢叶酸还原酶（methylenetetrahydrofolate reductase，MTHFR）基因C677T多态性分布特征，探讨其与儿童H型高血压的相关性。方法: 回顾性选取2021年1~7月于心血管内科住院、初次诊断未经治疗的121例原发性高血压儿童为研究对象，按基因型分为CC型组（19例）、CT型组（51例）和TT型组（51例）；按血清同型半胱氨酸（homocysteine，Hcy）水平分为H型高血压组（47例）和单纯高血压组（74例），比较各组间临床资料差异，分析MTHFR基因C677T多态性与儿童H型高血压的相关性。结果: 原发性高血压儿童T等位基因突变频率高于北京地区健康成年人群和中国汉族成年人群（P<0.001）。TT型组血清Hcy水平高于CC型组和CT型组（P<0.001）。H型高血压组血清Hcy水平高于单纯高血压组（P<0.001），且MTHFR基因C677T多为TT基因型，TT基因型与H型高血压的发生风险存在关联（OR=12.71，P<0.001）。H型高血压组和单纯高血压组间靶器官损伤发生率差异无统计学意义（P>0.05），但初次诊断时，H型高血压组即可存在多脏器受累情况，占11%（5/47）。结论: 原发性高血压儿童MTHFR基因C677T的T等位基因突变率高且与血清Hcy水平具有一定关联，TT基因型是儿童H型高血压的独立危险因素，与早期靶器官损伤严重程度可能相关。.
Keywords: Child; Gene polymorphism; Hyperhomocysteinemia; Methylenetetrahydrofolate reductase; Primary hypertension.