探讨5,10 -亚甲基四氢叶酸还原酶（MTHFR）基因多态性与胎盘细胞凋亡的相关性。

利用外部数据集初步探究MTHFR基因多态性对自身表达的影响。收集60名孕妇的胎盘组织，将其分为MTHFR突变型和野生型，HE染色观察两组胎盘组织的形态学变化，Tunnel染色评估胎盘细胞凋亡情况。通过Pearson相关分析探索MTHFR与细胞凋亡基因表达相关性。两组间比较采用独立样本t检验，发生率比较采用Fisher精确检验，相关性检验采用Pearson相关分析。

表达数量性状基因座（eQTL）分析结果显示，在21种类型组织中，C677T基因多态性与其表达量负相关。临床样本验证结果显示，突变型妊娠并发症发生率56.67%（17/30）高于野生型26.66%（8/30）；与突变型比较，野生型细胞凋亡指数（22.05%± 6.42%比35.82%± 8.45%）降低。在胎盘组织中，MTHFR的表达与凋亡抑制基因BCL2L2正相关（r = 0.211），与凋亡促进基因BAK1负相关（r = -0.182）。

MTHFR C677T基因多态性可能引起MTHFR表达下调，与胎盘细胞凋亡相关，是导致不良妊娠的潜在影响因素。

To investigate the correlation between the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene polymorphism and placental cell apoptosis.

Using an external dataset, the impact of MTHFR gene polymorphism on its self-expression was explored. We initially explored placental tissues from 60 pregnant women were collected and divided into MTHFR mutant and wild-type groups. Hematoxylin and eosin staining were used to observe the morphological changes in the placental tissues of the two groups. Tunnel staining was employed to assess the level of apoptosis in placental tissues. Pearson correlation analysis was used to explore the relationship between MTHFR and the expression of apoptosis-related genes.

Expression Quantitative Trait Loci (eQTL) analysis revealed a negative correlation between the C677T gene polymorphism and its expression in 21 of tissues. Clinical sample verification showed a higher incidence of pregnancy complications in the MTHFR mutant group (56.67%,17/30) compared to the wild-type group (26.66%, 8/30) . The apoptosis index in the mutant group (35.82%± 8.45%) was higher than in the wild-type group (22.05%± 6.42%) . In placental tissues, MTHFR expression was positively correlated with the anti-apoptotic gene BCL2L2 (r = 0.211) and negatively correlated with the pro-apoptotic gene BAK1 (r = -0.182) .

MTHFR C677T gene polymorphism may lead to downregulation of MTHFR expression, and be correlated to placental cell apoptosis, and potentially contributing to adverse pregnancies.