Application of Familial Y-STR Haplotype Mismatch Tolerance in Genealogy Inference / 法医学杂志

OBJECTIVES@#To provide a guideline for genealogy inference and family lineage investigation through a study of the mismatch tolerance distribution of Y-STR loci in Chinese Han male lineage.@*METHODS@#Three Han lineages with clear genetic relationships were selected. YFiler Platinum PCR amplification Kit was used to obtain the typing data of 35 Y-STR loci in male samples. The variation of Y-STR haplotypes in generation inheritance and the mismatch tolerance at 1-7 kinship levels were statistically analyzed.@*RESULTS@#Mutations in Y-STR were family-specific with different mutation loci and numbers of mutation in different lineages. Among all the mutations, 66.03% were observed on rapidly and fast mutating loci. At 1-7 kinship levels, the number of mismatch tolerance ranged from 0 to 5 on all 35 Y-STR loci, with a maximum step size of 6. On medium and slow mutant loci, the number of mismatch tolerance ranged from 0 to 2, with a maximum step size of 3; on rapidly and fast mutant loci, the number of mismatch tolerance ranged from 0 to 3, with a maximum step size of 6.@*CONCLUSIONS@#Combined use of SNP genealogy inference and Y-STR lineage investigation, both 0 and multiple mismatch tolerance need to be considered. Family lineage with 0-3 mismatch tolerance on all 35 Y-STR loci and 0-1 mismatch tolerance on medium and slow loci can be prioritized for screening. When the number of mismatch tolerance is eligible, family lineages with long steps should be carefully excluded. Meanwhile, adding fast mutant loci should also be handled with caution.

Microdeletions and vertical transmission of the Y-chromosome azoospermia factor region / 亚洲男科学杂志(英文版)

Spermatogenesis is regulated by several Y chromosome-specific genes located in a specific region of the long arm of the Y chromosome, the azoospermia factor region (AZF). AZF microdeletions are the main structural chromosomal abnormalities that cause male infertility. Assisted reproductive technology (ART) has been used to overcome natural fertilization barriers, allowing infertile couples to have children. However, these techniques increase the risk of vertical transmission of genetic defects. Despite widespread awareness of AZF microdeletions, the occurrence of de novo deletions and overexpression, as well as the expansion of AZF microdeletion vertical transmission, remains unknown. This review summarizes the mechanism of AZF microdeletion and the function of the candidate genes in the AZF region and their corresponding clinical phenotypes. Moreover, vertical transmission cases of AZF microdeletions, the impact of vertical inheritance on male fertility, and the prospective direction of research in this field are also outlined.

Incidence and genetic reproductive characteristics of AZFc microdeletion among patients with azoospermia or severe oligospermia / 中华医学遗传学杂志

OBJECTIVE@#To explore the incidence of azoospermia factor c (AZFc) microdeletion among patients with azoospermia or severe oligospermia, its association with sex hormone/chromosomal karyotype, and its effect on the outcome of pregnancy following intracytoplasmic sperm injection (ICSI) treatment.@*METHODS@#A total of 1 364 males with azoospermia or severe oligospermia who presented at the Affiliated Maternity and Child Health Care Hospital of Jiaxing College between 2013 and 2020 were subjected to AZF microdeletion and chromosome karyotyping analysis. The level of reproductive hormones in patients with AZFc deletions was compared with those of control groups A (with normal sperm indices) and B (azoospermia or severe oligospermia without AZFc microdeletion). The outcome of pregnancies for the AZFc-ICSI couples was compared with that of the control groups in regard to fertilization rate, superior embryo rate and clinical pregnancy rate.@*RESULTS@#A total of 51 patients were found to harbor AZFc microdeletion, which yielded a detection rate of 3.74%. Seven patients also had chromosomal aberrations. Compared with control group A, patients with AZFc deletion had higher levels of PRL, FSH and LH (P < 0.05), whilst compared with control group B, only the PRL and FSH were increased (P < 0.05). Twenty two AZFc couples underwent ICSI treatment, and no significant difference was found in the rate of superior embryos and clinical pregnancy between the AZFc-ICSI couples and the control group (P > 0.05).@*CONCLUSION@#The incidence of AZFc microdeletion was 3.74% among patients with azoospermia or severe oligospermia. AZFc microdeletion was associated with chromosomal aberrations and increased levels of PRL, FSH and LH, but did not affect the clinical pregnancy rate after ICSI treatment.

Y chromosome-related genetic diseases / 中华医学遗传学杂志

As a male-specific chromosome, the structure of Y chromosome is complex and lacks of recombination, with numerous repeating, amplifying and palindromic sequences. The research of Y chromosome is difficult and slow since there are few protein coding genes and a large amount of heterochromatin which has caused extreme difficulty for sequencing. In recent years, an increasing number of studies have been focused on the Y chromosome. With the completion of the sequencing of human Y chromosome, the rapid development of sequencing technology, and the composition of DNA sequences in human Y chromosomes and the determination of gene content. This paper has summarized the structural composition and genes function of human Y chromosome, as well as the related hereditary diseases, with an aim to provide reference for Y chromosome-related genetic research.

Forensic Application of Next Generation Sequencing Technology in the Typing of Y Chromosome Genetic Markers / 法医学杂志

The paternal inheritance characteristics of Y chromosome have been widely used in the forensic genetics field to detect the genetic markers in the non-recombining block, and used in the studies such as, genetic relationship identification, mixed stain detection, pedigree screen and ethnicity determination. At present, capillary electrophoresis is still the most common detection technology. The commercial detection kits and data analysis and processing system based on this technology are very mature. However, the disadvantages of traditional detection technology have gradually appeared with the rapid growth of bio-information amount, which promotes the renewal of forensic DNA typing technology. In recent years, next generation sequencing （NGS） technology has developed rapidly. This technology has been applied to various fields including forensic genetics and has provided new techniques for the detection of Y chromosome genetic markers. This article describes the current situation and application prospects of the NGS technology in forensic Y chromosome genetic markers detection in order to provide new ideas for future judicial practice.

Development and Forensic Application of EX20+30Y Kit / 法医学杂志

OBJECTIVES@#To develop a multiplex PCR amplification system (EX20+30Y for short) of 19 autosomes, 30 Y-STR loci plus the gender indicator, and evaluate its forensic application value.@*METHODS@#With the six-color fluorescence labeling technology, a multiplex amplification system of 19 autosomal STR loci and 30 Y-STR loci plus the gender indicator was constructed. Blood samples from 210 unrelated individuals, 69 daily case samples and standard samples 9948 and 9947A were collected for loci detection and analysis. The EX20+30Y multiplex amplification system was evaluated by its sensitivity, mixed sample detection ability, species specificity, balance, direct amplification ability, sample applicability and anti-inhibition ability.@*RESULTS@#Multiplex amplification of blood samples from 210 unrelated individuals by the detection system obtained accurate genotyping results. The detection sensitivity of standard samples was 0.125 ng and the species specificity was high. The 69 samples from daily cases were genotyped correctly. Moreover, standard sample 9948 could be accurately genotyped even if the samples contained a certain concentration of inhibitors.@*CONCLUSIONS@#The multiplex amplification system established in this study can conduct combined examination of 19 autosomes, 30 Y-STR loci plus the gender indicator with accurate genotyping and high sensitivity. It has a good forensic application prospect.

Genetic analysis of a fetus with mosaicism of structural aberration of Y chromosome / 中华医学遗传学杂志

OBJECTIVE@#To carry out genetic analysis and parental tracing for a fetus with an inconclusive chromosomal karyotype.@*METHODS@#The fetus and its parents were subjected to combined chromosomal karyotyping, chromosomal microarray analysis (CMA), fluorescence in situ hybridization (FISH) and multiplex PCR testing for Y chromosome microdeletions.@*RESULTS@#The fetus was found to have a karyotype of 45,X[18]/46,X,+mar[72]. CMA revealed that the fetus has carried a 2.6 Mb duplication at Yp11.32p11.31 and a 44.5 Mb deletion at Yq11.21q12. Interphase FISH of amniocytes confirmed the chromosomal mosaicism in the fetus, which has derived from Y chromosome. Multiplex PCR revealed deletion of AZFb and AZFc regions on the Y chromosome. No karyotypic abnormality was found with either parent at 400-band level.@*CONCLUSION@#Combined genetic analysis has delineated the aberrant karyotype in the fetus, which has facilitated prediction of its clinical phenotype and genetic counseling.

Polymorphism and Forensic Application of 11 Y-SNP in Guizhou Shui Ethnic Group / 法医学杂志

Objective To investigate the frequency distribution features of 11 Y-SNP of Guizhou Shui ethnic group, explore its genetic relationship with other ethnic groups and evaluate its forensic application value. Methods Multiplex amplification of the 11 Y-SNP of samples of 180 unrelated male individuals from Guizhou Shui ethnic group was performed with microsequencing technique. The frequency of haplogroup was calculated by direct counting method, and principal component analysis （PCA） of Guizhou Shui ethnic group and reference ethnic groups was performed by using Multi-variate statistical package （MVSP）. The Fst genetic distance between Guizhou Shui ethnic group and other ethnic groups was calculated with Arlequin v3.5. The phylogenetic tree was established with MEGA 4.0 software according to the Fst value. Results Six types of Y chromosome haplogroups were observed in total. Among which, the distribution frequency of O-M175 haplogroup was the highest （71.11%）, followed by C-M130 （25.00%）, and D-M174 （3.89%）. O1b-M268 （31.11%） and O2a2-IMS-JST021354 （28.33%） had a relatively high distribution frequency in O haplogroup. The paternal relationship between Guizhou Shui ethnic group and Guizhou Gelao ethnic group in the same language group was the closest. Conclusion The distribution of Y-SNP haplogroup of the Shui ethnic group in Guizhou has certain specificity, which can provide basic data for forensic biogeographic inference.

Genetic Structure Analysis of Y Chromosome STR and SNP in Population of Changshu / 法医学杂志

Objective To provide a theoretical basis for building a Y chromosome database in specific regions by analyzing the pedigree specific core haplogroup and region specific genetic structure in Changshu. Methods One thousand seven hundred and two samples from unrelated Han male individuals in Changshu were collected. Then 27 Y-STR were genotyped through YfilerTM Plus PCR Amplification Kit, Y-SNP haplogroup of each sample was speculated using Y-Predictor software and some samples were verified by amplification refractory mutation system-polymerase chain reaction （ARMS-PCR）. Results A total of 1 556 haplotypes were found on the 27 Y-STR genetic markers of the 1 702 samples. The haplotype diversity （HD） value was 0.999 827. DYS385 （0.933） had the highest gene diversity （GD） value while DYS438 （0.409） had the lowest. By the Y-Predictor software, all samples were confirmed to be from 162 sub-haplogroups of C, D, N, O, Q and R. Samples were randomly selected to verify the prediction results by the software and the prediction accuracy of Y-Predictor software was as high as 95.74%. Conclusion This study found that 27 Y-STR genetic markers have relatively high polymorphisms in the Changshu population, and have good forensic individual identification and paternity testing ability.

Preliminary study between Y chromosome haplogroups and chagasic cardiomyopathy manifestations in patients with Chagas disease

Abstract INTRODUCTION: Among patients with Chagas disease, men have a higher risk of worse pathological symptoms than women. We aimed to explore the role of the Y chromosome in men diagnosed with Chagas disease and assess the relationship between their ancestry and disease status. METHODS In this comparative study, we analyzed 150 men with unrelated non-chagasic disease (nCD) and 150 men with unrelated chagasic disease (CD). We assessed the serological diagnosis of Chagas disease, biochemical parameters, thoracic X-rays, electrocardiogram, and transthoracic echocardiography and determined the haplogroup by analyzing a set of 17 microsatellites from the Y chromosome. We examined the associations between common Y chromosome haplogroups and the clinical parameters of risk by logistic regression. RESULTS For all patients, the most common haplogroups were R1b (43%), G2a (9%), and E1b1b (9%). The R1b and G2a haplogroup was more frequent in men with nCD and CD, respectively. As expected, we observed a high proportion of symptomatic patients in the CD group independent of the haplogroups. Men from both groups classified as having the R1b haplogroup showed less clinical evidence of disease. Multivariate analysis showed that CD patients without R1b were about five times more likely to have a cardio-thorax index >0.5% (OR [odds ratio] = 5.1, 95% CI [confidence interval] = 3.31-8.17). Men without the R1b haplogroup were 2.5 times more likely to show EcoCG alterations (OR = 2.50, 95% CI = 0.16-3.94). CONCLUSIONS: Our results provided evidence that the R1b haplogroup may have a potential protective cardiovascular effect for its carriers.

High frequency of Y chromosome microdeletions in male infertility patients with 45,X/46, XY mosaicism

The mosaic 45,X/46,XY karyotype is a common sex chromosomal abnormality in infertile men. Males with this mosaic karyotype can benefit from assisted reproductive therapies, but the transmitted abnormalities contain 45,X aneuploidy as well as Y chromosome microdeletions. The aim of this study was to investigate the clinical and genetic characteristics of infertile men diagnosed with 45,X/46,XY mosaicism in China. Of the 734 infertile men found to carry chromosomal abnormalities, 14 patients were carriers of 45,X/46,XY mosaicism or its variants, giving a prevalence of 0.27% (14/5269) and accounting for 1.91% (14/734) of patients with a chromosomal abnormality. There were ten cases (71.43%, 10/14) of 45,X mosaicism exhibiting AZF microdeletions. Case 1 and Case 4 had AZFc deletions, and the other eight cases had AZFb+c deletions. A high frequency of Y chromosome microdeletions were detected in male patients with 45,X/46,XY mosaicism. Preimplantation genetic diagnosis should be offered to men having intracytoplasmic sperm injection for hypospermatogenesis caused by 45,X/46,XY mosaicism, to avoid the risk of transfering AZF microdeletions in addition to X monosomy in male offspring.

Prenatal diagnosis and genetic analysis of a fetus with der(X)t(X;Y)(p22.3;q11.2) / 中华医学遗传学杂志

OBJECTIVE@#To explore the pathogenesis and genetic characteristics of a fetus with a der(X)t(X;Y)(p22.3;q11.2) karyotype.@*METHODS@#G-banding karyotyping analysis, BoBs (BACs-on-Beads) assay, and single nucleotide polymorphism array (SNP-array) were used to delineate the structural chromosomal aberration of the fetus. The parents of the fetus were also subjected to karyotyping analysis.@*RESULTS@#The fetus and its mother were both found to have a karyotype of 46,X,add(X)(p22), while the father was normal. BoBs assay indicated that there was a lack of Xp22 but a gain of Yq11 signal. SNP-array confirmed that the fetus and its mother both had a 7.13 Mb deletion at Xp22.33p22.31 (608 021-7 736 547) and gain of a 12.52 Mb fragment at Yq11.221q11.23 (16 271 151-28 788 643).@*CONCLUSION@#The fetus was determined to have a karyotype of 46,X,der(X)t(X;Y)(p22.3;q11.2)mat. The combined use of various methods has facilitated delineation of the fetal chromosomal aberration and prediction of the risk prediction for subsequent pregnancy.

Genetic analysis of three children with disorders of sex development caused by structural rearrangements of Y chromosome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis of three children with disorders of sex development (DSD) in association with rare Y chromosome rearrangements.@*METHODS@#The three children, who all featured short stature and DSD, were subjected to G banding chromosomal karyotyping, multiplex PCR for Y chromosomal microdeletion, sequencing of the whole SRY gene, SNP-array analysis for genomic copy number variations, and fluorescence in situ hybridization (FISH).@*RESULTS@#The combined analysis revealed chromosomal abnormalities in all of the three children, including 46,X,t(X;Y)(p22.3;q11.2) in case 1, mos 45,X,der(7)pus dic(Y:7)(p11.3p22)del(7)(p21.2p21.3) del(7)(p12.3p14.3) [56]/45,X [44] in case 2, and mos 45,X [50]/46,X,idic(Y)(q11.22) [42]/47,X,idem×2 [4]/47,XYY [2] in case 3.@*CONCLUSION@#Combined use of genetic techniques can delineate complex rearrangements involving Y chromosome in patients featuring short stature and DSD. Above findings have enabled molecular diagnosis and genetic counseling for the patients.

Genetic Structure Analysis of Y-Chromosome STR and SNP in Population of Wujiang Area, Suzhou City / 法医学杂志

Objective To analyze the genetic phenotypes of Y-chromosome STR and SNP in Han male population of Wujiang area, Suzhou City and explore the genetic structure of population of Wujiang area for further examination of regional-specific Y-SNP genetic markers ancestor haplogroups. Methods Blood samples of 472 Wujiang area Han males were randomly collected and genotyped by YfilerTM Plus PCR Amplification Kit. The allele frequencies and haplotype frequencies of each locus were obtained using the direct calculation method. Y-SNP haplogroups of each sample were estimated using Y-Predictor software and verified through experiments by amplification refractory mutation system-polymerase chain reaction （ARMS-PCR）. Results A total of 453 haplotypes were found in the 27 Y-STR genetic markers in 472 Han males of Wujiang area. The haplotype diversity （HD） was 0.997 696 93, among which, the highest gene diversity （GD） value was DYF387S1a/b （GD=0.953 1） and the lowest was DYS438 （GD=0.321 8）. Based on genotyping data of 27 Y-STRs and 472 samples, 132 haplogroups from C, D, N, O and Q, etc downstream Y-SNP haplogroups were estimated and then verified through experiments. Conclusion This study is based on Y-chromosome STR haplotypes, and predicts Y-SNP haplogroups by Y-Predictor software, then uses ARMS-PCR to verify. Y-SNP genetic markers were introduced to achieve precise analysis of the genetic structure of male families in population of three towns in Wujiang area.

Genetic Polymorphisms and Mutations of 30 Y-STR Loci in Chinese Han Population / 法医学杂志

OBJECTIVES@#To investigate the genetic polymorphisms and mutations of 30 Y-STR loci in Chinese Han males and to evaluate its forensic application.@*METHODS@#The DNA extracted from blood samples of 1 005 unrelated males and 1 008 father-son pairs （1 949 individuals in all） in Chinese Han population were typed using developed 30 Y-STR loci identification system. The parameters of population genetics and the mutation rates of each locus were analysed statistically.@*RESULTS@#A total of 983 haplotypes were found in 1 005 unrelated males from Chinese Han population, of which 963 were unique. The overall haplotype diversity （HD） and discrimination capacity （DC） were 0.999 955 and 0.978 109, respectively. Totally 340 alleles were detected on 30 Y-STR loci, the value of gene diversity （GD） ranged from 0.410 3 to 0.952 3. The GD values of 24 out of the 30 loci were over 0.6. There were 30 269 allele transfers in 1 008 father-son pairs, one mutation in 68 father-son pairs, and the mutation of three father-son pairs occurred at two loci. On 26 Y-STR loci, 74 mutations were detected in 71 father-son pairs. The average mutation rates were 2.4×10⁻³ （95% CI： 1.9×10⁻³-3.1×10⁻³）. Seventy-three mutation events were one-step mutation （98.6%）, 1 mutation event was two-step mutation （1.4%）.@*CONCLUSIONS@#The multiplex PCR system with 30 Y-STR loci has high genetic polymorphism and low mutation rates in Chinese Han males. Therefore, the system shows important values in Y-STR database construction and population genetic research.

Diversidad del ADN mitocondrial en restos óseos prehispánicos / Mitochondrial DNA diversity in prehispanic bone remains on the eastern Colombian Andes

Resumen Introducción. El ADN antiguo que se extrae de los restos óseos humanos permite analizar la composición genética de las poblaciones precolombinas y determinar las dinámicas poblacionales que dieron origen a la diversidad de las poblaciones contemporáneas. Objetivo. Determinar la diversidad genética y la relación con otras comunidades contemporáneas y antiguas de América, de los restos óseos asociados al Templo del Sol en Sogamoso, Colombia. Materiales y métodos. Se analizaron 13 individuos pertenecientes al periodo precolombino muisca (siglos IX-XVI d. C.), provenientes de los alrededores del Templo del Sol en Sogamoso, Boyacá, Andes orientales colombianos. Se amplificó el ADN mitocondrial (ADNmt) y se determinaron los polimorfismos de la longitud de los fragmentos de restricción (Restriction Fragment Length Polymorphism, RFLP) para los cuatro haplogrupos amerindios (A, B, C y D). Además, se amplificaron y analizaron los marcadores autosómicos, incluida la amelogenina, y los marcadores de los polimorfismos de repeticiones cortas en tándem (Short Tandem Repeat, STR) del cromosoma Y. Resultados. El haplogrupo A fue el linaje mitocondrial más frecuente en esta población, seguido de los haplogrupos B y C; no se detectó el haplogrupo D. Los análisis de variación genética indicaron una diversidad semejante a la de las poblaciones pertenecientes a la familia lingüística chibcha, contemporánea en Colombia y Centroamérica. Se logró hacer la determinación molecular del sexo de los individuos estudiados y compararla con los datos osteológicos. Con una sola excepción, los datos bioantropológicos y moleculares concordaron. Conclusiones. Estos resultados aportan nuevos elementos a la hipótesis del origen centroamericano de los grupos chibchas del altiplano cundiboyacense con base en marcadores genéticos, y permitieron establecer el sexo y las relaciones de parentesco.

Abstract Introduction: DNA extracted from ancient human bones allows to analyze the genetic makeup of preColumbian populations and to determine the dynamics that gave rise to the diversity of contemporary populations. Objective: To determine the genetic diversity of skeletal remains associated with the Templo del Sol (Sun Temple) and their relationship with other contemporary and ancient communities of America. Materials and methods: We analyzed 13 individuals belonging to the pre-Columbian Muisca Period (IX-XVI centuries AD) from the vicinities of the Templo del Sol (Sun Temple) (Sogamoso, Boyacá) in the eastern Colombian Andes. Mitochondrial DNA was amplified and RFLPs were performed in order to type the four traditional Amerindian haplogroups (A, B, C and D). In addition, autosomal markers including amelogenin and Y-chromosome STRs were amplified. Results: Among the observed mitochondrial lineages, haplogroup A was the most frequent, followed by haplogroups B and C; no evidence of haplogroup D was found. The genetic variation analysis indicated a similar diversity of pre-Columbian Muiscas to that of contemporary populations belonging to the Chibcha linguistic family from Colombia and Central America. Molecular sexing was accomplished and it was compared to osteological data. With only one exception, anthropological and molecular data were consistent. Conclusions: Our results contribute new genetic elements supporting the hypothesis of Central American origin of the Chibcha groups of the Cundiboyacense plateau, and allowed sex typing and kinship evaluations.

Sixty-six Biallelic Genetic Markers on Y chromosome by MALDI-TOF-MS / 法医学杂志

OBJECTIVES@#To analyse the genetic polymorphisms of 66 biallelic genetic markers on Y chromosome in Eastern Chinese Han population, and evaluate their values in forensic application.@*METHODS@#Genotyping of 66 biallelic genetic markers on Y chromosome was studied in 205 unrelated males of Eastern Chinese Han population by multiplex PCR combined matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS）. The allele frequencies on the loci to be tested were calculated by direct counting method, and the gene diversity （GD） and haplotype diversity （HD） were calculated by corresponding formulas. The haplotypes of this system were tested by software Arlequin v3.5.2.2 and the comparison of population genetics were analyzed.@*RESULTS@#A total of 60 biallelic genetic markers on Y chromosome were polymorphic in males of Eastern Chinese Han population, and the ranges of GD were from 0.038 5 to 0.501 9. Eighty-five different haplotypes were observed and the HD was 0.970 3. The differences of partial SNP loci between the Han population of Eastern China and that of Xinjiang and Guangdong were statistically significance.@*CONCLUSIONS@#Sixty biallelic genetic markers and the detection system can complementally provide genetic information in kinship testing and individual identification. The MALDI-TOF-MS technology is able to type biallelic genetic markers.

Incidence of Y-chromosome microdeletions in children whose fathers underwent vasectomy reversal or in vitro fertilization with epididymal sperm aspiration: a case-control study / Incidência de microdeleções do cromossomo Y em filhos de pais que passaram por reversão de vasectomia ou fertilização in vitro com aspiração do epidídimo: um estudo caso-controle

ABSTRACT Objective To evaluate the incidence of Y-chromosome microdeletions in individuals born from vasectomized fathers who underwent vasectomy reversal or in vitro fertilization with sperm retrieval by epididymal aspiration (percutaneous epididymal sperm aspiration). Methods A case-control study comprising male children of couples in which the man had been previously vasectomized and chose vasectomy reversal (n=31) or in vitro fertilization with sperm retrieval by percutaneous epididymal sperm aspiration (n=30) to conceive new children, and a Control Group of male children of fertile men who had programmed vasectomies (n=60). Y-chromosome microdeletions research was performed by polymerase chain reaction on fathers and children, evaluating 20 regions of the chromosome. Results The results showed no Y-chromosome microdeletions in any of the studied subjects. The incidence of Y-chromosome microdeletions in individuals born from vasectomized fathers who underwent vasectomy reversal or in vitro fertilization with spermatozoa recovered by percutaneous epididymal sperm aspiration did not differ between the groups, and there was no difference between control subjects born from natural pregnancies or population incidence in fertile men. Conclusion We found no association considering microdeletions in the azoospermia factor region of the Y chromosome and assisted reproduction. We also found no correlation between these Y-chromosome microdeletions and vasectomies, which suggests that the assisted reproduction techniques do not increase the incidence of Y-chromosome microdeletions.

RESUMO Objetivo Avaliar a incidência de microdeleções do cromossomo Y em indivíduos nascidos de pais vasectomizados submetidos à reversão de vasectomia ou fertilização in vitro com recuperação de espermatozoides por aspiração do epidídimo (aspiração percutânea de espermatozoides do epidídimo). Métodos Estudo caso-controle que compreende crianças do sexo masculino de casais em que o homem havia sido previamente vasectomizado e escolheu reversão da vasectomia (n=31) ou fertilização in vitro com recuperação espermática por aspiração percutânea de espermatozoides do epidídimo (n=30) para obtenção de novos filhos, e um Grupo Controle de crianças do sexo masculino de homens férteis com vasectomia programada (n=60). A pesquisa de microdeleções do cromossomo Y foi realizada por reação em cadeia da polimerase nos pais e filhos, avaliando 20 regiões do cromossomo. Resultados O resultado não revelou microdeleções do cromossomo Y em qualquer indivíduo estudado. A incidência de microdeleções do cromossomo Y em indivíduos nascidos de pais vasectomizados que sofreram reversão de vasectomia ou fertilização in vitro com espermatozoides recuperados pela aspiração percutânea de espermatozoides do epidídimo não diferiu entre os grupos, e não houve nenhuma diferença entre indivíduos controle nascidos de gestações naturais ou incidência populacional em homens férteis. Conclusão Não foi encontrada nenhuma associação considerando microdeleções da região do fator de azoospermia no cromossomo Y e reprodução assistida. Não houve correlação entre microdeleções do cromossomo Y e vasectomia, o que sugere que as técnicas de reprodução assistida não aumentam a incidência de microdeleções do cromossomo Y.

Microdeletion and Mutation of Y Chromosome in Full Sibling Identification / 法医学杂志

OBJECTIVES@#To explore the identification method of full sibling between two males with microdeletion and mutation of Y chromosome.@*METHODS@#DNA were extracted from two samples. The type testing of Y-STR and autosomal STR were performed. Full sibling between two individuals was calculated by IBS, ITO and discriminant functions methods.@*RESULTS@#There were 2 loci mutations existed in 33 Y-STR loci and one of the two samples had 19 loci deletions. The IBS of two samples was 53 and greater than the threshold which was 42; FSI was 1.36×10¹⁶ and far greater than 19. The discriminant function of full sibling-unrelated individual DFS2 was greater than DR2, which meant the two individuals tend to be full sibling.@*CONCLUSIONS@#The methods of IBS, ITO and discriminant functions of full sibling-unrelated individual can be used comprehensively to provide more reliable expert opinion in microdeletion and mutation of Y chromosome in full sibling identification.

Research Progress on Gene Alterations of Amelogenin Locus in Gender Identification / 法医学杂志

There are two kinds of amelogenin gene mutation, including mutation in primer-binding region of amelogenin gene and micro deletion of Y chromosome encompassing amelogenin gene, and the latter is more common. The mechanisms of mutation in primer-binding region of amelogenin gene is nucleotide point mutation and the mechanism of micro deletion of Y chromosome encompassing amelogenin gene maybe non-allelic homologous recombination or non-homologous end-joining. Among the population worldwide, there is a notably higher frequency of amelogenin gene mutations in Indian population, Sri Lanka population and Nepalese population which reside within the Indian subcontinent. Though amelogenin gene mutations have little impact on fertility and phenotype, they might cause incorrect result in gender identification. Using composite-amplification kit which including autosomal STR locus, amelogenin gene locus and multiple Y-STR locus, could avoid wrong gender identification caused by amelogenin gene mutation.