• Biomedical Science Letters
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• v.29 no.4
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• pp.302-313
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• 2023

Y chromosomal short tandem repeat (Y-STR) markers have been developed continuously to complement forensic DNA analyses and population genetic studies. Initially, we collected data from previously reported Korean population Y-STR haplotype studies on 1133 individuals. We then conducted a marker expansion analysis using a dataset from the Y-STR Haplotype Reference Database (YHRD), covering up to 29 Y-STRs, referred to as Ymax. Additionally, we examined the impact of rapidly mutating (RM) Y-STRs included in this expanded marker set on the discrimination capacity. We observed that marker expansions both with (0.9896), and without (0.9510), RM Y-STR improved the discrimination capacity. Subsequently, we focused on 16 individuals belonging to seven distinct groups sharing identical haplotypes. These particular haplotypes had been previously identified among 476 unrelated males using 23 Y-STR markers from the PowerPlex^® Y23 System. We expanded the marker panel up to Ymax to explore how discrimination improved with an expansion of Y-STR markers for these 16 individuals. Among the expanded markers, DYS627, which had high discriminatory power, had a high mutation rate (1.10 × 10^-2) and high gene diversity (0.83). In contrast, DYF387S1 displayed high gene diversity (0.95) but a relatively low mutation rate (2.80 × 10^-3). We propose that these findings will be valuable in the selection of suitable Y-STR markers, depending on the objectives of forensic analyses. Additionally, the presence of frequently observed Y-haplotypes in Korean population will facilitate statistical interpretation in Y-STR DNA profiling.

• Journal of Genetic Medicine
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• v.7 no.1
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• pp.59-66
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• 2010

Purpose: Quantitative fluorescent polymerase chain reaction (QF-PCR) allows for the rapid prenatal diagnosis of common aneuploidies. The main advantages of this assay are its low cost, speed, and automation, allowing for large-scale application. However, despite these advantages, it is not a routine method for prenatal aneuploidy screening in Korea. Our objective in the present study was to validate the performance of QF-PCR using short tandem repeat (STR) markers in a Korean population as a means for rapid prenatal diagnosis. Material and Methods: A QF-PCR assay using an Elucigene kit (Gen-Probe, Abingdon, UK), containing 20 STR markers located on chromosomes 13, 18, 21, X and Y, was performed on 847 amniotic fluid (AF) samples for prenatal aneuploidy screening referred for prenatal aneuploidy screening from 2007 to 2009. The results were then compared to those obtained using conventional cytogenetic analysis. To evaluate the informativity of STR markers, the heterozygosity index of each marker was determined in all the samples. Results: Three autosomes (13, 18, and 21) and X and Y chromosome aneuploidies were detected in 19 cases (2.2%, 19/847) after QF-PCR analysis of the 847 AF samples. Their results are identical to those of conventional cytogenetic analysis, with 100% positive predictive value. However, after cytogenetic analysis, 7 cases (0.8%, 7/847) were found to have 5 balanced and 2 unbalanced chromosomal abnormalities that were not detected by QF-PCR. The STR markers had a slightly low heterozygosity index (average: 0.76) compared to those reported in Caucasians (average: 0.80). Submicroscopic duplication of D13S634 marker, which might be a unique finding in Koreans, was detected in 1.4% (12/847) of the samples in the present study. Conclusion: A QF-PCR assay for prenatal aneuploidy screening was validated in our institution and proved to be efficient and reliable. However, we suggest that each laboratory must perform an independent validation test for each STR marker in order to develop interpretation guidelines of the results and must integrate QF-PCR into the routine cytogenetic laboratory workflow.