Post-graduate Program in Genetics and Molecular Biology, Department of Biosciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
INAGEMP - Instituto Nacional de Genética Médica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
J Matern Fetal Neonatal Med. 2020 Oct;33(20):3431-3438. doi: 10.1080/14767058.2019.1573791. Epub 2019 Mar 7.
Cândido Godói (CG) is a small city in South Brazil in which natural twin births (both monozygotic and dizygotic) occur at an unusually high rate and the twin trait runs through the local families, which are mostly European descendants. We have argued that a genetic founder effect must have occurred during the settlement of CG and that genetic factors may help to explain the familial aggregation of twinning in that city. The aim of this study was to evaluate single nucleotide polymorphisms (SNPs) related to folliculogenesis (rs6166:C > T in , rs11031006:G > A near , and rs17293443:T > C in ) and successful pregnancies (rs2010963:C > G in , rs1800629:G > A in , rs1801131:T > G and rs1801133:G > A in ) in mothers from CG. Forty-four mothers of twins (the case group) and 102 mothers of singletons (the control group) from CG were investigated. Genotypes were determined using real-time PCR (TaqMan SNP Genotyping Assay). For all SNPs, the distributions of the genotypic and allelic frequencies were similar between cases and controls. Interestingly, a deviation from the Hardy-Weinberg equilibrium was detected for SNP rs11031006:G > A near in the control population. Different combinations of risk alleles and haplotypic analyses were homogeneously distributed between cases and controls. These results suggest a lack of association between the seven studied SNPs and twin births in CG. However, we hypothesized that other genetic variants related to folliculogenesis or successful pregnancies may be involved in this phenomenon. Identifying such genetic components may be important not only for the Brazilian "Twins' Town" but also for a better understanding of twinning in general.
坎迪多·戈多伊（CG）是巴西南部的一个小城，这里的自然双胞胎（包括同卵双胞胎和异卵双胞胎）出生率异常高，而且双胞胎特征在当地以欧洲后裔为主的家庭中普遍存在。我们认为，在 CG 的定居过程中一定发生了遗传奠基者效应，遗传因素可能有助于解释该市双胞胎的家族聚集现象。本研究旨在评估与卵泡发生（ 中的 rs6166：C>T、 附近的 rs11031006：G>A 和 rs17293443：T>C）和成功妊娠（ 中的 rs2010963：C>G、 rs1800629：G>A、 rs1801131：T>G 和 rs1801133：G>A）相关的单核苷酸多态性（SNP）在 CG 地区母亲中的情况。共调查了来自 CG 的 44 对双胞胎母亲（病例组）和 102 位单胎母亲（对照组）。使用实时 PCR（TaqMan SNP 基因分型检测）确定基因型。对于所有 SNP，病例组和对照组的基因型和等位基因频率分布相似。有趣的是，在对照组中， 附近的 SNP rs11031006：G>A 偏离了 Hardy-Weinberg 平衡。病例组和对照组之间不同的风险等位基因组合和单倍型分析分布均匀。这些结果表明，在 CG 中，七个研究的 SNP 与双胞胎出生之间没有关联。然而，我们假设与卵泡发生或成功妊娠相关的其他遗传变异可能参与了这一现象。确定这些遗传成分不仅对巴西的“双胞胎之乡”很重要，而且对全面了解双胞胎现象也很重要。
