[Association between MTHFR gene polymorphism and primary hypertension in children]

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.

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.

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).

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.