DNA-LAB Gabon Clinic, Libreville, Gabon.
Chemistry-Biochemistry Service, Department of Fundamental and Mixed Sciences, Faculty of Medicine, University of Health Sciences, Libreville, Gabon.
Sci Rep. 2023 Nov 15;13(1):19938. doi: 10.1038/s41598-023-47395-z.
Short tandem repeats (STRs) are repeating DNA sequences used in forensic human identity testing and the diagnosis of aneuploidies. Many STRs like Penta D and TPOX are used routinely for paternity tests, but these tests are not widely used in sub-Saharan Africa. In this study we recruited individuals from Gabonese families seeking a paternity test. After DNA extraction from buccal swabs, we genotyped samples using a panel of 22 STRs. A total of 115 unrelated subjects from 39 families were included. Allele frequencies of the 22 STR loci were determined in unrelated Gabonese subjects. The most polymorphic loci were D21S11 (16 alleles) and FGA (17 alleles), while D3S1358 and TH01 loci were less polymorphic, with five alleles each. Deviation from Hardy-Weinberg equilibrium was observed for TPOX, D3S1358, CSFPO and D7S820 loci. We reported tri-allelic patterns that indicate aneuploidies at a combined frequency of 4% (4/115) with 3% for Penta D (1/35) and 3% for TPOX (3/102). Furthermore, we identified a new tri-allelic genotype 5-8-16 for the Penta D locus located on chromosome 21 in a healthy subject. In addition, we observed three tri-allelic variants of TPOX, located on chromosome 2, in healthy subjects, namely 8-10-11, 8-9-10, and 8-8-10. Our study revealed unsuspected polymorphic variations in Penta D and TPOX for the first time in Gabon, raising several questions about chromosomal disorders. Further population genetics studies are needed in Gabon to better characterize these variations, both qualitatively and quantitative.
短串联重复序列（STRs）是法医人类身份检测和非整倍体诊断中使用的重复 DNA 序列。许多 STRs，如 Penta D 和 TPOX，常用于亲子鉴定，但这些测试在撒哈拉以南非洲地区并不广泛使用。在这项研究中，我们招募了来自加蓬家庭的寻求亲子鉴定的个体。从口腔拭子中提取 DNA 后，我们使用 22 个 STR 面板对样本进行基因分型。总共包括 39 个家庭的 115 个无关个体。在无关的加蓬个体中确定了 22 个 STR 基因座的等位基因频率。最多态性的基因座是 D21S11（16 个等位基因）和 FGA（17 个等位基因），而 D3S1358 和 TH01 基因座的多态性较低，每个基因座有 5 个等位基因。TPOX、D3S1358、CSFPO 和 D7S820 基因座观察到偏离 Hardy-Weinberg 平衡。我们报告了三等位基因模式，表明在 4%（4/115）的合并频率下存在非整倍体，其中 Penta D（1/35）为 3%，TPOX（3/102）为 3%。此外，我们在一名健康个体中发现了位于 21 号染色体上的 Penta D 基因座的新三等位基因基因型 5-8-16。此外，我们在健康个体中观察到 TPOX 的三个三等位基因变异体，位于 2 号染色体上，分别为 8-10-11、8-9-10 和 8-8-10。我们的研究首次在加蓬发现 Penta D 和 TPOX 存在意想不到的多态性变化，这引发了一些关于染色体疾病的问题。需要在加蓬进行进一步的群体遗传学研究，以更好地定性和定量地描述这些变化。
