[Association of eight single nucleotide polymorphisms of chromosomes 20 and X with androgenetic alopecia among ethnic Han Chinese from Yunnan].

OBJECTIVE: To assess the association of 8 single nucleotide polymorphisms (SNPs) from chromosomes X and 20 with androgenetic alopecia among ethnic Han population from Yunnan province. METHODS: An eight-SNP co-amplification protocol was developed for the genotyping with a SNaPshot platform. A case-control study was carried out for the 8 SNPs from chromosomes X and 20 in 115 androgenetic alopecia cases and 125 healthy controls. Statistical analysis was conducted with SPSS17.0, Haploview4.2, SHEsis and MDR software. RESULTS: No association was found between the two groups with regard to the 4 SNPs located on the X chromosome. The genotypic frequencies of rs2180439, rs913063 and rs1160312 were significantly different between the two groups (P < 0.05). The frequency of T allele of rs2180439 was significantly higher in the case group (P < 0.05). The frequencies of A alleles of rs913063 and rs1160312 were significantly higher in the case group (P < 0.05). The haplotypes of C-T-C-G, T-C-C-G and T-T-A-A based on rs6137444-rs2180439-rs913063-rs1160312 showed significant difference between the two groups (P <0.05). rs6137444, rs21804393 and rs1160312 have a strong association with androgenetic alopecia. CONCLUSION: The 4 SNPs located on chromosome X were all monomorphic among ethnic Hans from Yunnan. The rs6152, rs16990427, rs1352015, rs1385699 SNPs located on chromosome 20 are associated with androgenetic alopecia in the same population. Individuals with T allele of rs2180439 and A allele of rs913063 and rs1160312 are more likely to develop androgenetic alopecia.

[Identification of null and duplicated alleles for forensic DYS549, DYS527 and DYS459 in male infertility population].

DYS549, DYS527, and DYS459 loci, located on the azoospermia factor (AZF) region and widely used in forensic and pedigree analysis, may be specifically altered in infertile patients, which will obscure the result of individual identification using Y-STR (Y chromosome short tandem repeat). In this study, we determined the AZF polymorphism by STS(-/-) (sequence tagged site) and DAZ, CDY1 gene copy numbers, and screened the samples by 14 Y-STR loci to disclose the unusual genotype of Y-STR in male infertility population. The 240 infertile males including non-obstructive azoospermia, severe oligozoospermia and congenital bilateral absence of vas deferens (CBVAD) were analyzed with a modified multiplex PCR system for AZF microdeletion STSs. AZF microdeletions were found in 40 cases (16.67%) (AZFa deletion, two cases; AZFb deletion, two cases; AZFc deletion, 30 cases; AZFb+c deletion, six cases). Further screening by the 14 Y-STR loci in samples with microdeletions, we found DYS549 allelic loss in all the cases with AZFb deletion, DYS527 and DYS459 allelic loss in all the cases with AZFc deletion, DYS549, DYS527, and DYS459 allelic loss in all the cases with AZFb+c deletion. Ten patients (4.17%) with AZFc partial duplication (one CBVAD case, two non-obstructive azoospermia cases, seven severe oligozoospermia cases) were found by DAZ and CDY1 gene dosage analysis. In conclusion, the unusual patterns of DYS549, DYS527, and DYS459 are caused by genetic defects rather than experimental bias. Revealing the locus heterogeneity in male infertility population can enrich the Y-STR database and assist in interpreting abnormal STR genotype in forensic DNA testing.

Toward male individualization with rapidly mutating y-chromosomal short tandem repeats.

Relevant for various areas of human genetics, Y-chromosomal short tandem repeats (Y-STRs) are commonly used for testing close paternal relationships among individuals and populations, and for male lineage identification. However, even the widely used 17-loci Yfiler set cannot resolve individuals and populations completely. Here, 52 centers generated quality-controlled data of 13 rapidly mutating (RM) Y-STRs in 14,644 related and unrelated males from 111 worldwide populations. Strikingly, >99% of the 12,272 unrelated males were completely individualized. Haplotype diversity was extremely high (global: 0.9999985, regional: 0.99836-0.9999988). Haplotype sharing between populations was almost absent except for six (0.05%) of the 12,156 haplotypes. Haplotype sharing within populations was generally rare (0.8% nonunique haplotypes), significantly lower in urban (0.9%) than rural (2.1%) and highest in endogamous groups (14.3%). Analysis of molecular variance revealed 99.98% of variation within populations, 0.018% among populations within groups, and 0.002% among groups. Of the 2,372 newly and 156 previously typed male relative pairs, 29% were differentiated including 27% of the 2,378 father-son pairs. Relative to Yfiler, haplotype diversity was increased in 86% of the populations tested and overall male relative differentiation was raised by 23.5%. Our study demonstrates the value of RM Y-STRs in identifying and separating unrelated and related males and provides a reference database.

[Analysis of null alleles for 17 Y chromosome-short tandem repeat loci in infertile males].

OBJECTIVE: To investigate the characteristics of null allele for 17 Y-chromosomal short tandem repeats (Y-STR) loci in a group of infertile males. METHODS: Two hundred thirty six infertile males featuring non-obstructive azoospermia and severe oligozoospermia were analyzed with an AmpFISTR ((R)) Yfiler (TM) kit. Deletions of azoospermia factor (AZF) fragments were confirmed with Y chromosome sequence-tagged sites (STSs) analysis using modified multiplex PCR. RESULTS: The overall prevalence of AZF microdeletions was 16.95% (40/236). In the non-obstructive azoospermia group, 13 cases had AZFc deletion, 6 cases had AZFb+c deletion, 2 cases had AZFa deletion, 1 case had AZFb deletion. In the severe oligozoospermia group, 17 cases had AZFc deletion and 1 had AZFb deletion. No AZFa+b+c deletion was detected. Forty cases showed null alleles by scanning of the 17 STR loci. Deletions of DYS438, DYS439, DYS437, DYS389I and DYS389II were found in the 2 cases with AZFa deletion. In patients with AZFb deletion, DYS392 and DYS385a/b were found deleted. Deletions of DYS448 were detected in all of the 30 cases with AZFc deletion. Deletions of DYS392, DYS385a/b, and DYS448 were found in 6 cases with AZFb+c deletion. CONCLUSION: Deletions of the Y chromosome AZF regions are associated with azoospermia and severe oligozoospermia. Null allele due to complete absence of AZFa, AZFb and AZFc regions may lead to misinterpretation in the sexual assault cases. Revealing the locus heterogeneity in male infertility population can enrich the Y-STR database and facilitate interpretation STR data in forensic DNA testing.

Relationship between the CAG repeat polymorphism in the androgen receptor gene and acne in the Han ethnic group.

BACKGROUND: The modulatory domain of the human androgen receptor (AR) gene contains a polymorphic CAG repeat coding for a polyglutamine tract which is inversely correlated with transcriptional activity of the AR. Androgens acting through the AR play a crucial role in the pathogenesis of acne vulgaris. We therefore investigated the relationship between CAG repeat polymorphism in the AR gene and acne susceptibility. METHODS: 206 acne patients and 200 controls participated in the study. Genomic DNA was extracted from peripheral blood lymphocytes of individual patients, and the CAG repeat region was amplified by polymerase chain reaction (PCR) using fluorescence-labeled primers. Samples were then run on an ABI 377 gene scan analysis gel with an internal molecular-weight marker. Ten male samples were chosen randomly for sequencing to confirm the number of CAG repeats. The 2-sample independent t test was used to analyze the data. RESULTS: The mean number of the CAG repeat in the AR was 22.07 (14-28) in the controls and 20.61 (13-26) in the male acne group. There was a significant correlation between the CAG repeat length and male acne. No significant difference was observed between female patients and their controls. CONCLUSION: The results suggest that the AR gene CAG repeat polymorphism may be one of the candidate genetic markers for male acne susceptibility in the Han population.

[DNA polymorphism detection of Papaver somniferum L using fluorescent amplified fragment length polymorphism].

OBJECTIVE: To detect DNA polymorphism of Papaver somniferum L using fluorescent Amplified Fragment Length Polymorphism. METHODS: Genomic DNA was isolated using the AxyPrep DNA Kit, double-digested by two restrictional endonucleases (Eco RI and Mse I) and ligated to oligonucleotide adapters. After Pre-amplification and selective amplification, the DNA fragments were separated by capillary electrophoresis using the CEQ8000 DNA Fragment Analyzer. RESULTS: More than 20 fragments of highly polymorphic products were obtained by 8 pairs of primer from 64 selective amplifying primer pairs. CONCLUSION: The fluorescent AFLP technique can be used to detect the DNA polymorphism of Papaver somniferum.

Crossed polydactyly type I caused by a point mutation in the GLI3 gene in a large Chinese pedigree.

Polydactyly is one of the most common forms of congenital malformation in humans, and is displayed by 119 disorders. Crossed polydactyly (CP) is defined as the coexistence of preaxial and postaxial polydactyly with a difference in the axes of polydactyly between the hands and feet. In an effort to map the gene responsible for CP, we studied a seven-generation Chinese family of 56 individuals, 28 of whom were affected. A thorough search with highly informative polymorphic markers showed no recombination among the affected members with the markers on chromosome 7p15-q11.23, but no linkage with chromosomes 2q31, 7q36, 13q, and 19p. Mutation analysis showed a substitution mutation of 1927C --> T in exon 12 of the GLI3 gene, which is predicted to pretruncate the GLI3 protein. This mutation has variable phenotypes of polydactyly, indicating that other genetic factors also contribute to the diversity of polydactyly phenotypes. Our results increase the phenotypic spectrum caused by GLI3 mutations and are important for the analysis and understanding of the etiology of these limb malformations.

Association of the C-344T polymorphism of CYP11B2 gene with essential hypertension in Hani and Yi minorities of China.

BACKGROUND: Aldosterone synthase (CYP11B2) is a key enzyme in the biosynthesis of aldosterone. Recently, a C-344T polymorphism in the promoter region of the CYP11B2 gene has been reported to be in association with high blood pressure. We investigated the association between this polymorphism and essential hypertension in Hani (n=305 individuals) and Yi (n=233 individuals) minorities of China. METHODS: CYP11B2 genotyping with polymerase chain reaction-restriction fragment length polymorphism was performed in 267 normotensive subjects and 271 essential hypertensive subjects. At the same time, the T(-344)C polymorphism detection in 33 subjects was also performed by sequencing. RESULT: The frequency of CYP11B2 C-344T genotype in normotensive controls and essential hypertensive cohort in Hani population were TT: 0.729 vs. 0.610; CT + CC: 0.271 vs. 0.390, respectively. The frequency of CYP11B2 C-344T genotype in normotensive controls and essential hypertensive cohort in Yi population were TT: 0.612 vs. 0.475; CT + CC: 0.388 vs. 0.525, respectively. The frequency of CC + CT genotype in the essential hypertensive group was significantly higher than that in the normotensive controls in both Hani and Yi populations (P<0.05). CONCLUSION: The -344C allele of the CYP11B2 may play a role in genetic predisposition to developing essential hypertension in Hani and Yi minorities of China.

[The polymorphism of Y chromosome and mtDNA distribution among two Bai populations].

In the same ethnic group, people residing at different places may have genetic difference. The difference can be the results of migration and admixture events happened in history. To clarify the genetic relationship and micro-evolution of two Bai ethnic populations residing in Yunnan and Hunan province respectively,we investigated their genetic difference from paternal and maternal genealogy with six other ethnic groups as outgroups. Fourteen loci from mtDNA and thirteen loci from Y chromosome were selected for genotyping using PCR-RFLP methods. Result showed that H6 and H8 are the same dominant Y chromosome haplotypes in two Bai groups. However,the distribution of mtDNA haplogroups showed difference between two Bai populations. D, B, M8 are the predominant haplogroups in Hunan Bai ethnic population, whereas M, G, F are dominant in Yunnan Bai ethnic population. Principal Component (PC) analysis based on the Y chromosome haplotypes showed that two Bai ethic populations cluster together. It shows a close paternal genetic relationship between two Bai ethnic populations. From the mtDNA PC plot, it is clear that Hunan Bai is close to Hunan Han and Tujia, whereas Yunnan Bai is close to ethnic groups living in Yunnan province. The difference of mtDNA haplogroup distribution in two Bai people may reflect the maternal gene flow between ethnic groups living in Hunan province after the ancestors of Hunan Bai migrated from Yunnan province to Hunan province 800 years ago.

The distribution of Y chromosome haplogroups in the nationalities from Yunnan Province of China.

The genetic structure of 26 identified nationalities from Yunnan Province of China was studied using Y chromosome haplogroups. A total of 12 haplogroups were obtained in 1214 male samples from all the nationalities. The genetic relationships among 26 nationalities were studied. The ethnic groups were compared according to their different ancient lineages. The ancient lineages had their own characteristics in the distribution of Y chromosome haplogroups. Our results showed that Yunnan Province has great genetic diversity in its people. The ethnic groups differ from each other in the number of haplogroups and haplogroup frequencies. The genetic evidence was in agreement with the study of linguistic and historical records.

[Principal component analysis of Y-chromosome haplotype distribution in 18 ethnic groups in Yunnan Province].

Based on the historical records, 18 of the 26 ethnic groups in Yunnan Province are the descendant populations of three ancient tribes, Bai-Yue, Bai-Pu and Di-Qiang, linguistically belonging to the Daic, Austro-Asiatic and Tibeto-Burman, respectively. In order to trace the origins of these native ethnic groups, a total of 13 East Asian specific Y-chromosome biallelic markers were used to study the genetic structure of 20 local populations covering all the 18 ethnic groups in Yunnan Province. Haplotypes were analysis by PCR-RFLP method. Our results showed that H11 and H12 were the predominant haplotypes in the descendant populations of Bai-Yue tribe. H5, H6 and H8 were the dominant haplotypes in Di-Qiang descendants, and the frequencies of H6, H8 and H11 were very high in the descendant populations of Bai-Pu. To investigate relationships among 20 populations, a three dimensional PC analysis were performed based on the distribution of the 13 haplotypes. All populations were divided into two clusters in the PC plot. The first cluster was mainly composed by the descendant populations of Bai-Yue, and the second one was mainly composed by the descendants of Di-Qiang tribe. This result indicated that Bai-Yue and Di-Qiang's paternal lineage had different origins, which was in agreement with the historical documents and linguistic classification.

[Gene frequencies of 4 STR loci in Tibetan population of Yunnan province].

OBJECTIVE: To investigate the gene frequencies of 4 STR loci in Tibetan population of Yunnan. METHODS: Multiple polymerase chain reaction (PCR), denaturing polyacrylamide gel electrophoresis and silver staining were used to detect D21S11, D8S1179, D16S539 and LPL loci. DNA samples collected from 105 unrelated Tibetan individuals in Yunnan province were analyzed. RESULTS: At D21S11, D8S1179, D16S539 and LPL loci, 13, 8, 7, 6 alleles and 33, 21, 16 and 9 genotypes were observed, respectively. The genotype distribution of the 4 STR was in accordance with the Hardy-Weinberg equilibrium. CONCLUSION: The high combined discrimination power and exclusion power of the four loci in Tibetan population make multi-PCR detection a valuable tool for forensic identity, genetics and anthropology.