Y-chromosomal microdeletions, associated with oligozoospermia or azoospermia, are usually de novo deletions in the affected patients. We report here the rare case of an affected father who transmitted a Y-chromosomal microdeletion to at least two of his three sons naturally and who also fathered a daughter. The extent of the deletion, which was determined with new STS-primers and covers 3.5 Mb, was identical in the father and his azoospermic sons. To determine any possibly modifying influence of other genes involved in spermatogenesis, we analysed two polymorphisms of the DAZL gene, the autosomal homologue of the deleted DAZ gene. DAZL and DAZ might be functionally related to each other. However, we found identical polymorphisms in exon 2 and 3 of the DAZL gene, in both father and his sons, corresponding to the most prevalent genotype in fertile men. Thus, other genes or environmental factors must modify spermatogenesis in men with identical Y-chromosomal microdeletions. 相似文献
Background: Investigation of haplotype/allele frequency data of Y-STR loci in ethnically diverse populations is essential for forensic reference database construction and genetic application. However, the population genetic characteristics of the Chinese Miao minority from Guizhou Province remain uncharacterised.
Aim: To assess forensic characteristics for 23 Y-Chromosomal STR loci in Guizhou Miao and explore population genetic relationships with geographically neighbouring populations.
Subjects and methods: Twenty-three Y-Chromosomal STRs were genotyped using the Powerplex® Y23 system in 103 unrelated Chinese Miao males from Guizhou Province, southwest China. Haplotypes and forensic parameters were obtained. Population relationships of Guizhou Miao with others were revealed using AMOVA and an MDS plot.
Results: A total of 96 haplotypes were identified with overall haplotype diversity (HD) and discrimination capacity (DC) of 0.9985 and 0.9320, respectively. Genetic differentiation was observed with most of the comparison populations, prominently for Guizhou Shui.
Conclusion: The 23 Y-STR loci were highly polymorphic and discriminating in the Guizhou Miao population and could be used for forensic practice and population genetic studies. Population relationship analysis revealed Guizhou Miao had a close genetic relationship with geographically close Guizhou Gelao, as well as Han majorities derived from different regions. 相似文献
Y-chromosomal SNP (Y-SNP), with its stable inheritance and low mutation, can provide Supplementary information in forensic investigation. While commonly used Y-chromosomal STR haplotypes show their limitations, typing of Y-SNP would become a powerful complement. In this study, a 16-plex Y-SNP typing system based on allele-specific PCR (AS-PCR) was developed to discriminate four dominant Y-chromosomal haplogroups (C-M130, D-CTS3946, N-M231, and O-M175) and 12 predominant sub-haplogroups of O-M175 (O1a-M119, O1a1a1a-CTS3265, O1b-M268, O1b1a2-Page59, O2-M122, O2a1-L127.1, O2a1b-F240, O2a1b1a1-CTS5820, O2a2-P201, O2a2b1a1-M177, O2a2b1a1a1a-Y17728, O2a2b1a2-F114). A series of experimental validation studies including sensitivity, species specificity, male-female mixture and inhibition were performed. The discrimination of the typing system was preliminarily proved with a haplogroup diversity of 0.9239. Altogether, the Y-SNP typing system based on AS-PCR should be capable of distinguishing China’s dominant Y-chromosomal haplogroups in a rapid and reliable manner, thus can be employed as a useful complement in forensic casework. 相似文献
Y-chromosomal haplogroups determined by Y-chromosomal single nucleotide polymorphisms (Y-SNPs) allow paternal lineage identification and paternal biogeographic ancestry inference, which has attracted a lot of interest in the forensic community. Recently, a comprehensive Y-SNP tool with dominant markers targeting haplogroups in R, E and I branches has been reported, which allows the inference of 640 Y haplogroups. It had a very good performance and could provide a high level of Y haplogroup resolution in most populations. However, the predominant haplogroups in the Chinese populations are O, C and N, suggesting that more Y-SNPs under these clades are needed to achieve the population-specific high resolution. Herein, aiming at the Chinese population, we presented a largely improved custom Y-SNP MPS panel that contains 256 carefully ascertained Y-SNPs based on our previous studies, and evaluated this panel via a series of tests, including the tests for concordance, repeatability, sensitivity, specificity, and stability, as well as the mixture, degraded and case-type sample analysis. The preliminary developmental validation demonstrated that this panel was highly reliable, sensitive, specific, and robust. In the sensitivity test, even when the DNA input was reduced to as low as 0.5 ng, the sample could still be assigned to the correct Y haplogroup. For mixture analysis, even the 1:99 (Male: Female) mixtures had no effects on the assignation of the Y haplogroup of the male contributor. In summary, this assay has provided a high-resolution Y-chromosomal haplogrouping workflow to determine a male’s paternal lineage and/or paternal biogeographic ancestry and could be widely used for Chinese Y-chromosomal haplogroups dissection. 相似文献
目的 分析9个新Y染色体短串联重复序列(Y short tandem repeats,Y-STR)基因座的序列结构,及其在潮汕地区汉族人群中的遗传多态性分布,评价其法医学应用价值.方法 应用PCR反应,对潮汕地区汉族159名无关男性个体的血样进行基因分型,采用直接计数法计算9个Y-STR基因座的等位基因频率和单体型频率.结果 9个Y-STR基因座(DYS522、DYS549、DYS556、DYS565、DYS568、DYS570、DYS594、DYS593、DYS588)均为单拷贝,并分别检测出7、5、5、4、6、9、4、4、8个等位基因,基因多样性(gene diversity,GD)在0.1434~0.7994间;共检出136种单体型;累计单体型GD值为0.997.另对30个2代父子家系调查显示:同一家系成员9个Y-STR基因座单体型一致,未观察到基因突变.结论 9个Y-STR基因座具有较高的鉴别效能,适合作为法医学应用的遗传标记. 相似文献
We have already coamplified minimal haplotypes (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385I/II), two additional loci, namely, DYS438, DYS439, and Amelogenin, in a single PCR using the Y-PLEX 12 kit. We investigated 107 unrelated male individuals from the Uigur ethnic group and studied the allelic frequency distribution and haplotype diversity of 11 Y-chromosomal STRs. A number of 43 alleles (nine STR loci) and 27 phenotypes (including DYS385) were detected, with frequencies ranging from 0.0092 to 0.6296. A total of 103 haplotypes were identified, among which 99 were individual-specific and four haplotypes were found twice. The haplotype diversity for these 12 Y-STR loci was 0.9993. 相似文献
A newly discovered case of heteropaternal superfecundation is reported. In a case of disputed paternity involving a pair of male twins, the results suggested that the twins had different biological fathers. Heteropaternal superfecundation is rarely observed among humans; our laboratory has encountered only one case of heteropaternal twins in 78 cases of twin disputed paternities. Therefore, when it comes to the paternity testing of dizygotic twins, the possibility of heteropaternity should be kept in mind. 相似文献
To compare the frequency of chromosomal heteromorphisms in reproductive failure and fertile control individuals in Northeast China, and investigate the impact on reproductive failure
Methods
1751 males and 1424 couples with reproductive failure (n = 4599) and 777 fertile control individuals in Northeast China were enrolled. Chromosome karyotype analysis was performed on peripheral blood lymphocytes with standard G-banding. Additionally, C-banding was performed with heterochromatin heteromorphisms, and NORs-banding with satellites/stalks variations. Multiplex polymerase chain reaction (PCR) adopted for the amplification using nine specific sequence tagged sites (STS) were used to detect Y-chromosome microdeletions with Y chromosome variations (Yqh±). At the same time, 38 heteromorphic probands’ family members were recalled for performing karyotype analysis and to be surveyed for their detailed reproductive history.
Results
The frequency of chromosomal heteromorphisms in reproductive failure patients (2.74 %, 126/4599) was of no statistically significant difference as compared with fertile control individuals (2.06 %, 16/777) (P > 0.05). Eight cases of Y variation (Yqh±) probands with Y-chromosomal microdeletions were detected among 44 reproductive failure patients and 6 fertile control men. In the 38 recalled families, the probands of fathers or mothers, even some of their brothers or sisters, had the same heteromorphic karyotypes as probands’ despite that they didn’t have any adverse reproductive history.
Conclusions
There was no statistically significant difference in frequency of chromosomal heteromorphisms between reproductive failure and fertile control individuals in Northeast China. Males with Y variations (Yqh±) should be ordered Y-chromosomal microdeletions detection. Through the analysis of 38 recalled families, we can also conclude that chromosomal heteromorphisms were not the impact factors for reproductive failure. 相似文献