Department of Forensic Medicine, Molecular Techniques Unit, Wroclaw Medical University, Poland.
Department od Microbiology, Wroclaw Medical University, Poland.
Adv Clin Exp Med. 2020 Feb;29(2):251-256. doi: 10.17219/acem/115078.
Down syndrome (DS) is the most frequent cause of intellectual disability. In 95% of cases, it is caused by simple trisomy of chromosome 21 resulting from nondisjunction of chromosomes in meiotic division. Currently, the molecular and cellular mechanisms responsible for the phenomenon of nondisjunction are unknown.
To investigate the incidence of 5 single-nucleotide polymorphisms (SNPs) of the MTHFR gene in a population of Polish mothers who had given birth to children with trisomy 21 in comparison with a control group of women with healthy offspring.
The test material comprised venous blood collected from mothers who had given birth to a child with DS (study group, n = 130) as well as from women who had given birth to children without trisomy 21 (control group, n = 88). DNA was isolated using a kit manufactured by Qiagen. Amplification was carried out using a Qiagen Multiplex PCR Kit (Qiagen); genotyping was performed using SNaPshot Genotyping MasterMix (Applied Biosystems).
No statistically significant differences were observed in the frequency of genotypes between the examined groups in terms of the polymorphisms of the MTHFR gene.
In the Polish population studied, no relationship was found between the occurrence of particular genotypes of the MTHFR gene, i.e., 677CT, 1298AC, rs3737964, rs4846048, and rs1994798, in women and the birth of children with trisomy 21. The results contradict the validity of research on polymorphisms of the MTHFR gene as potential predisposing factors for the occurrence of trisomy 21 in children.
唐氏综合征（DS）是智力障碍最常见的原因。在 95%的病例中，它是由染色体 21 的简单三体性引起的，这是减数分裂中染色体不分离的结果。目前，导致非分离现象的分子和细胞机制尚不清楚。
研究波兰母亲生育 21 三体患儿的人群中 MTHFR 基因的 5 个单核苷酸多态性（SNP）的发生率，并与生育正常后代的对照组妇女进行比较。
测试材料包括来自生育 DS 患儿的母亲（研究组，n=130）和生育非 21 三体患儿的母亲（对照组，n=88）的静脉血。使用 Qiagen 试剂盒提取 DNA。使用 Qiagen Multiplex PCR Kit（Qiagen）进行扩增，使用 SNaPshot Genotyping MasterMix（Applied Biosystems）进行基因分型。
在 MTHFR 基因的多态性方面，研究组和对照组之间在基因型频率方面没有观察到统计学上的显著差异。
在波兰人群中，未发现 MTHFR 基因特定基因型的发生（即 677CT、1298AC、rs3737964、rs4846048 和 rs1994798）与女性生育 21 三体儿之间存在关系。研究结果否定了 MTHFR 基因多态性作为儿童 21 三体发生潜在易感因素的有效性。
