Biomedical subjects

Zaw Tun

Publications and source records attributed to Zaw Tun.

2 recordsLinked to original sources

PubMed2003

Asian online Y-STR Haplotype Reference Database.

For several years Y-chromosomal microsatellites (short tandem repeats, STRs) have been well established in forensic practice. In this context, the genetic characteristics of the Y chromosome (i.e. its paternal inheritance and lack of recombination) render STRs particularly powerful. However, genetic differences between male populations appear to be larger for Y-STRs than for autosomal STRs, a fact that is most likely due to the higher sensitivity of Y-chromosomal lineages to genetic drift (Forensic Sci Int 118 (2001) 153). The assessment of probabilities for matches between haplotyped male persons or traces/persons requires the typing of a large number of haplotypes in the appropriate reference populations. The haplotype data of a large number of European as well as South and North American populations have been collected and are continuously published online (Y-STR Haplotype Reference Database--YHRD; http://www.ystr.org). The most recent multicentric effort has led to the establishment of an Asian YHRD (http://www.ystr.org/asia) which has been available since January 2002. All databases are maintained and curated at the Institute of Legal Medicine, Humboldt-University, Berlin and will soon be fused to a global repository including populations from all continents.

Asia↗

PubMed2002

The specific mitochondrial DNA polymorphism found in Klinefelter's syndrome.

Hypervariable segments of mitochondrial DNA (mtDNA) (HV1 and HV2) were analyzed in Klinefelter's syndrome and compared to normal population data. One pair of samples consisting of a Japanese mother and affected son with Klinefelter's syndrome (involved in a criminal case), and seven unrelated DNA samples from Caucasian Klinefelter males (two involved in criminal cases and five diagnosed) were collected in Japan and the United States. The diagnosis of Klinefelter's syndrome was established previously by multiplex XY-STR typing detecting two X alleles and one Y allele in the samples. Haplotype analysis of the mtDNA sequence in Klinefelter males was found to be identical, unique, and specific, as it was not found in the normal population. Astonishingly, family data exhibited that the haplotype of the mtDNA in the son was apparently different from the mother's, suggesting that the mtDNA of Klinefelter male would not be inherited from mother to son. Our data indicate that possible interaction of the sex chromosome and the mtDNA exists, and suggests that the specific mtDNA haplotype could cause the abnormal cell to fertilize and reproduce itself.

DNA, Mitochondrial↗