Frequency of Y chromosome microdeletions and chromosomal abnormalities in infertile Thai men with oligozoospermia and azoospermia

Aim： To investigate the possible causes of oligozoospermia and azoospermia in infertile Thai men, and to find the frequencies of Y chromosome microdeletions and cytogenetic abnormalities in this group. Methods： From June 2003 to November 2005, 50 azoospermic and 80 oligozoospermic men were enrolled in the study. A detailed history was taken for each man, followed by general and genital examinations. Y chromosome microdeletions were detected by multiplex polymerase chain reaction （PCR） using 11 gene-specific primers that covered all three regions of the azoospermic factor （AZFa, AZFb and AZFc）. Fifty men with normal semen analysis were also studied. Karyotyping was done with the standard G- and Q-banding. Serum concentrations of follicle stimulating hormone （FSH）, luteinizing hormone （LH）, prolactin （PRL） and testosterone were measured by electrochemiluminescence immunoassays （ECLIA）. Results： Azoospermia and oligozoospermia could be explained by previous orchitis in 22.3%, former bilateral cryptorchidism in 19.2%, abnormal karyotypes in 4.6% and Y chromosome microdeletions in 3.8% of the subjects. The most frequent deletions were in the AZFc region （50%）, followed by AZFb （33%） and AZFbc （17%）. No significant difference was detected in hormonal profiles of infertile men, with or without microdeletions. Conclusion： The frequencies of Y chromosome microdeletions and cytogenetic abnormalities in oligozoospermic and azoospermic Thai men are comparable with similarly infertile men from other Asian and Western countries.

The prevalence of azoospermia factor microdeletion on the Y chromosome of Chinese infertile men detected by multi-analyte suspension array technology

Aim： To develop a high-throughput multiplex, fast and simple assay to scan azoospermia factor （AZF） region microdeletions on the Y chromosome and establish the prevalence of Y chromosomal microdeletions in Chinese infertile males with azoospermia or oligozoospermia. Methods： In total, 178 infertile patients with azoospermia （nonobstructed）, 134 infertile patients with oligozoospermia as well as 40 fertile man controls were included in the present study. The samples were screened for AZF microdeletion using optimized multi-analyte suspension array （MASA） technology. Results： Of the 312 patients, 36 （11.5%） were found to have deletions in the AZF region. The rnicrodeletion frequency was 14% （25/178） in the azoospermia group and 8.2% （11/134） in the oligospermia group. Among 36 patients with microdeletions, 19 had deletions in the AZFc region, seven had deletions in AZFa and six had deletions in AZFb. In addition, four patients had both AZFb and AZFc deletions. No deletion in the AZF region was found in the 40 fertile controls. Conclusion： There is a high prevalence of Y chromosomal microdeletions in Chinese infertile males with azoospermia or oligozoospermia. The MASA technology, which has been established in the present study, provides a sensitive and high-throughput method for detecting the deletion of the Y chromosome. And the results suggest that genetic screening should be advised to infertile men before starting assisted reproductive treatments.

Routine screening for classical azoospermia factor deletions of the Y chromosome in azoospermic patients with Klinefelter syndrome

Aim： To evaluate the occurrence of classical azoospermia factor （AZF） deletions of the Y chromosome as a routine examination in azoospermic subjects with Klinefelter syndrome （KS）. Methods： Blood samples were collected from 95 azoospermic subjects with KS （91 subjects had a 47,XXY karyotype and four subjects had a mosaic 47,XXY/46, XY karyotype） and a control group of 93 fertile men. The values of testosterone, follicle stimulating hormone （FSH） and luteinizing hormone （LH） were measured. To determine the presence of Y chromosome microdeletions, polymerase chain reaction （PCR） of five sequence-tagged site primers （sY84, sY 129, sY 134, sY254, sY255） spanning the AZF region, was performed on isolated genomic DNA. Results： Y chromosome microdeletions were not found in any of the 95 azoosperrnic subjects with KS. In addition, using similar conditions of PCR, no microdeletions were observed in the 93 fertile men evaluated. The level of FSH in KS subjects was higher than that in fertile men （38.2 ± 10.3 mIU/mL vs. 5.4 ±2.9 mIU/mL, P 〈 0.001） and the testosterone level was lower than that in the control group （1.7 ±0.3 ng/mL vs. 4.3 ± 1.3 ng/mL, P 〈 0.001）. Conclusion： Our data and review of the published literature suggest that classical AZF deletions might not play a role in predisposing genetic background for the phenotype of azoospermic KS subjects with a 47,XXY karyotype. In addition, routine screening for the classical AZF deletions might not be required for these subjects. Further studies including partial AZFc deletions （e.g. gr/gr or b2/b3） are necessary to establish other mechanism underlying severe spermatogenesis impairment in KS.

Y chromosome microdeletions in azoospermic patients with Klinefelter's syndrome

Aim： To study the occurrence of Y chromosome microdeletions in azoospermic patients with Klinefelter＇s syndrome （KFS）. Methods： Blood and semen samples were collected from azoospermic patients with KFS （n = 14） and a control group of men of proven fertility （n = 13）. Semen analysis was done according to World Health Organization （WHO） guidelines. Blood samples were processed for karyotyping, fluorescent in situ hybridization （FISH） and measurement of plasma follicle stimulating hormone （FSH） by radioimmunoassay. To determine Y chromosome microdeletions, polymerase chain reaction （PCR） of 16 sequence tagged sites （STS） and three genes （DFFRY, XKRY and RBM1 Y） was performed on isolated genomic DNA. Testicular fine needle aspiration cytology （FNAC） was done in selected cases. Results： Y chromosome microdeletions spanning the azoospermia factor （AZF）a and AZFb loci were found in four of the 14 azoospermic patients with KFS. Karyotype and FISH analysis revealed that, of the four cases showing Y chromosome microdeletion, three cases had a 47,XXY/46,XY chromosomal pattern and one case had a 46,XY/47,XXY/48,XXXY/48,XXYY chromosomal pattern. The testicular FNAC of one sample with Y chromosome microdeletion revealed Sertoli cell-only type of morphology. However, no Y chromosome microdeletions were observed in any of the 13 fertile men. All patients with KFS had elevated plasma FSH levels. Conclusion： Patients with KFS may harbor Y chromosome microdeletions and screening for these should be a part of their diagnostic work-up, particularly in those considering assisted reproductive techniques. （Asian JAndrol 2006 Jan; 8： 81-88）

Clinical and pathological correlation of the microdeletion of Y chromosome for the 30 patients with azoospermia and severe oligoasthenospermia

Aim: To review the accumulated 30 patients with different area of Y chromosome microdeletions, focusing on their correlation with the clinical and pathological findings. Methods: A total of 334 consecutive infertile men with azoospermia (218 patients) and severe oligoasthenospermia (116 patients) were screened. Complete physical and endocrinological examinations, general chromosome study and multiplex polymerase chain reaction assay to evaluate the Y chromosome microdeletion were performed. Ten patients received testicular biopsy. Then the clinical and pathological findings were analyzed with reference to the areas of Y chromosome microdeletion. Results: There is a decline of the percentage of sperm appearing in semen in the group that the gene deletion region from AZFc to AZFb. The clinical evidence of the impairment (decreased testicular size and elevated serum FSH) is also relevantly aggravated in this group. However, the pathology of testicular biopsy specimen was poorly correlated with the different deletion areas of the Y chromosome, which may be due to the limited number of specimens. Conclusion: The clinical correlation of spermatogenic impairment to the different AZF deletion regions may provide the information for the infertile couples in pre-treatment counseling.

Gonadal dysgenesis in Turner syndrome with Y-chromosome mosaicism:Two case reports

BACKGROUND Turner syndrome(TS)has a variety of different karyotypes,with a wide range of phenotypic features,but the specific karyotype may not always predict the phenotype.TS with Y chromosome mosaicism may have mixed gonadal dysgenesis,and the mosaicism is related to the potential for gonadoblastoma.CASE SUMMARY In this case report,we report two cases of TS with different karyotypes and gonadal dysgenesis.Patient 1 had obvious virilization,and was positive for the SRY gene,but her karyotype in peripheral blood lymphocytes was 45X.Patient 2 had a mosaic karyotype,45X/46X,dic(Y:Y)(p11.3:p11.2),and the proportion of Y-bearing cells was 50%in peripheral blood lymphocytes,but the patient had normal female external genitalia and streaky gonads,with no genital virilism.Different tissues in the same TS individual may exhibit different ratios of mosaicism.The gonadal determination and differentiation of mosaic TS are primarily dependent on the predominant cell line in the gonads.CONCLUSION In TS patients with virilization,it is necessary to test at least two to three tissues to search for cryptic Y material.

Multiplex PCR Screening of Y Chromosome Microdeletions in Azoospermic Patients

Objective To develop a multiplex PCR protocol for routine screening of microdeletions on the Y chromosome Methods Five multiplex sets were established and Y chromosome microdeletions screening were carried out in 26 azoospermic men who undertook ICSI and 30 azoospermic men who undertook testicular biopsy. Results In 56 azoospermic men, 5 patients were found with AZFc/DAZ microdeletions, 2 patients were accompanied by AZFc/DAZ and AZFb/RBM1 double microdeletion, and 1 patient had only single sY153 microdeletion. Conclusion The multiplex PCR protocol presented in this study is an easy and reliable method for detecting microdeletions on the Y chromosome. Routine screening for microdeletions on the Y chromosome in azoospermic patients is essential.

Y-chromosomal microdeletions and partial deletions of the Azoospermia Factor c(AZFc)region in normozoospermic,severe oligozoospermic and azoospermic men in Sri Lanka

Aim： To assess for the first time the occurrence of Y chromosomal microdeletions and partial deletions of the Azoospermia Factor c （AZFc） region in Sri Lankan men and to correlate them with clinical parameters. Methods： In a retrospective study, we analyzed 96 infertile men （78 with non-obstructive azoospermia） and 87 controls with normal spermatogenesis. AZFa, AZFb, AZFc and partial deletions within the AZFc region were analyzed by multiplex polymerase chain reaction （PCR） according to established protocols. Results： No AZFa, AZFb or AZFc deletions were found in the control group. Seven patients in the group of infertile men were found to have deletions as following： one AZFa, two AZFc, two AZFbc and two AZFabc. The relative distribution of these patterns was significantly different compared with that found in the German population. Extension analysis confirmed that the deletions occurred according to the current pathogenic model, gr/gr deletions were found to be equally present both in the patients （n = 4） and in the control group （n = 4）. One b2/b3 deletion was found in the patient group. Conclusion： These results suggest that the frequency and pattern of microdeletions of the Y chromosome in Sri Lankan men are similar to those found in other populations and confirm that gr/gr deletions are not sufficient to cause spermatogenetic failure. （Asian J Androl 2006 Jan; 8： 39-44）

Quick recovery and characterization of cell-free DNA in seminal plasma of normozoospermia and azoospermia： implications for non-invasive genetic utilities

We established a quick and reliable method for recovering cell-free seminal DNA （cfsDNA）, by using the binding-washing-elution procedure on the DNA purification column. Low variations （below 15%） among the triplicate values of cfsDNA quantity verified the reproducibility of our cfsDNA recovery method. Similar cfsDNA yield and size distribution between seminal plasma acquired by filtration and centrifugation confirmed the presence of cfsDNA. To investigate the general characterization of cfsDNA, the quantitation and size distribution of cfsDNA from normozoospermic and azoospermic semen were analyzed by real-time PCR and electrophoresis, respectively. CfsDNA concentration in semen with normozoospermia （n = 11） was 1.34 ± 0.65 μg ·mL^-1, whereas a higher cfsDNA concentration was observed in azoospermia （2.56 ± 1.43 μg ·mL^-1, n = 9）. The continuous distribution of DNA fragments ranging from -1 kb to 15 kb and a spectrum of multiples of 180-bp fragments were observed in each normozoospermic and azoospermic sample. Distinct characteristic DNA ladder fragmentations in some azoospermic samples implicated that cfsDNA originate partly from apoptotic cells. CfsDNAs of 36 selected azoospermic patients with known information of Y chromosome microdeletion were subjected to the same microdeletion analysis by multiplex PCR and PCR amplification of sY114 （1 450 bp）. All multiplex PCR reactions with cfsDNA amplified successfully and provided the same result as leukocyte DNA. PCR amplification of sY114 gave a 1 450-bp amplicon as expected. Our data suggested the potential use of cfsDNA in search of biomarker or diagnostic procedures.

Vertical transmission of the Yq AZFc microdeletion from father to son over two or three generations in infertile Han Chinese families

This study was carried out to analyze the vertical transmission of Yq AZFc microdeletions from father to son in infertile Han Chinese families to investigate genetic factors and family background affecting fertility status.The peripheral blood of infertile males in 19 Han families was extracted and screened with modified multiplex polymerase chain reaction （PCR）. Family trees were drawn according to fertility status and clinical characteristics of the subjects. The vertical transmission of Yq AZFc microdeletions was detected in six cases of 19 investigated families （31.6%,6/19）. Although both fathers and sons showed a similar type of Yq AZFc deletion,the fathers were fertile,whereas the sons were infertile and showed severe oligozoospermia. The vertical transmission of Yq AZFc microdeletion from fertile fathers to infertile sons over generations is not rare. This has different effects on fertility status in fathers and sons in Han Chinese families. Both genetic factors and family background affect spermatogenetic phenotypes.

PCR analysis of Yq microdeletions in infertile males, a study from South India

AIM: To estimate the frequency of microdeletions in the long arm of Y-chromosome of 20 infertile males from South India. METHODS: Polymerase chain reaction (PCR) amplification using Y-specific STS of azoospermia factor (AZF) regions i.e., SY 84 for AZFa, SY 127 for AZFb and SY 254 for AZFc. RESULTS: Of the 20 infertile subjects 3 (15 %), one azoospermic and two oligozoospermic, showed microdeletions in the AZF region of Y-chromosome. CONCLUSION: The frequency of deletions involving AZF region of the Y-chromosome is 15 % in azoospermic and severely oligozoospermic infertile men. PCR amplification of AZF locus is useful for the diagnosis of microdeletions in the Y-chromosome.

SRY-negative 45,X/46,XY adult male with complete masculinization and infertility:A case report and review of literature

BACKGROUND 45,X/46,XY mosaicism is a rare chromosomal abnormality with a wide range ofphenotypes in both males and females, from normal individuals with differentdegrees of genital ambiguity to those who show signs of Turner’s syndrome.More rarely, cases of 45,X/46,XY mosaicism with a normal-appearing malephenotype are not found until a chromosome test is performed to investigate thecause of male infertility.CASE SUMMARY In this study, a 29-year-old male patient with complete azoospermia is reported.Chromosomal analyses of his lymphocytes revealed the karyotype 45,X[93%]/46,X,+mar(Y)[7%]. In addition, Y chromosome-specific markers, such as SRY,ZFY, AZFa, AZFb and AZFc, were not observed in his blood DNA according tomultiplex polymerase chain reaction test. A literature review identified several45,X/46,XY cases with a normal-appearing male phenotype, most of whom werediagnosed during infertility investigation. However, the present case is the firstSRY-negative 45,X/46,XY male case diagnosed during a premarital medicalexamination.CONCLUSION This finding further suggests that sex determination is a complex processregulated by multiple genetic and environmental factors.

GENETIC POLYMORPHISM OF SIX Y CHROMOSOMAL STR IN CHINESE HUI ETHNIC GROUP

Objective To study genetic polymorphism of 6 Y chromosomal STR in Hui ethnic group living in Ningxia Hui ethnic autonomous region, in order to evaluate their usefulness in forensic science and enrich the Chinese genetic information resources. Methods We investigated 101 unrelated, healthy, male individuals of Hui ethnic group and studied their allelic frequency distribution and haplotype diversity of 6 Y chromosomal STR. Primer for each loci was labeled with the fluorescent by FAM (blue) or TAMRA(yellow). The data of Hui ethnic group were generated co-amplification, GeneScan, genotype, and genetic distribution analysis. Results 31 alleles and 43 phenotype(DYS385) were detected, with the frequencies ranging from 0.0099-0.7129. Out of a total of 101 individuals, 96 showed different haplotypes; 91 were unique; 5 were found 2 times. The haplotype diversity for 6 Y-STR loci was 0.9990. Conclusion The date obtained can be valuable for individual identification, paternity testing in forensic fields and for population genetics because of 6 Y-STR loci high polymorphism.

Yq AZF microdeletions in male infertility:An update on the phenotypic spectrum,epidemiology and diagnostics

According to the latest data,globally 15%of couples have infertility and male infertility contributes to 10%of all cases.Infertility can be caused by certain biological changes in the gonads and the reproductive system like azoospermia,oligospermia,asthenospermia,teratozoospermia and hypospermatogenesis.Genetic causes of azoospermia include chromosomal abnormalities,Y chromosome microdeletions and deletion or other mutations of Y-linked genes.The maximum number of the genes are located in the azoospermia factor region of the long arm(Yq)of the Y chromosome.Y chromosome microdeletion is known as the second major genetic cause of spermatogenetic failure.This article aims to review the latest updates on the involvement of Yq microdeletions in male infertility.The diagnostics,prevalence and phenotypic spectrum related to Yq gene microdeletions are discussed.

Studies on in situ PCR Detected by the BrdU Antibody Technique

Using the BrdU antibody technique followed by an immuno-chemical staining(BAT),the amplification o f DNA fragments specific to human Y chromosome on cell specimen slides was efficiently detected. Whether direct BrdU incorporation into PCR products or in situ hybridization with PCR products on slides, the amplified targetDNA fragments of specimen were visualized by BAT under the microscope. The availability of BAT and differencesin the sensitivity and efficiency between BAT and dig--if-dUTP labeling in cell in situ PCR were disCussed.

An investigation of 10 Y-STR loci and the detection of specific haplotype frequencies in Turkish population

This study is to survey 10 Y-STR loci in 241 males from Turkey. In this study, the 241 healthy and unrelated males living in different parts of Turkey for at least three generations were included. Genomic DNAs were isolated from peripheral blood samples by standard phenol-chloroform extraction method. 10 Y-STR loci including DYS19, DYS385a/b, DYS388, DYS389I/II, DYS390, DYS391, DYS392, DYS393, and YCAIIa/b were analyzed by using PCR and denaturing PAGE. Allele frequencies, gene diversities and haplotype frequencies were analyzed. Gene diversity per locus varied from 0.5788 (DYS388) to 0.8903 (DYS385a/b). The numbers of haplotypes in minHt recommended by YCC and Ht10 have been 208 and 186, respectively. When our minHt haplotypes frequencies compared with the other seven populations, we have found statistically significant differences between our results and other populations (P 0.05). We suggest that an alternative haplotype designated as aHt maybe alternative to minHt in respect of its Y-STR content with the highest gene diversity value. The aHt haplotype has found a higher discriminatory potential than minHt haplotype with a better Pd combined value (0.9999936 vs 0.9999836) and has higher average gene diversity per locus (0.7834 vs 0.7518) in Turkish population. aHt haplotype can be proposed as an alternative to minHt in paternity testing and forensic medicine applications involving Turkish male population. This study has also provided additional information to the framework of variation involving 10 Y-STR loci as well as a further contribution to the Y-STR database for Turkish male population.

Effects of age on segregation of the X and Y chromosomes in cultured lymphocytes from Chinese men

Chromosome malsegregation in binucleated lymphocytes is a useful endpoint to evaluate age effect on genetic stability. However, the investigations on chromosome malsegregation in binucleated lymphocytes from Chinese are scarce. In this study, peripheral blood lym- phocytes were collected from 14 old （60-70 years） and 10 young （22-26 years） healthy Chinese men. To detect malsegregation of the sex chromosomes, multi-color fluorescence in situ hybridization （FISH） was performed on binucleated lymphocytes, cytokinesis-blocked by cytochalasin B at the first mitosis after phytohaemagglutinin stimulation. Compared with that in young men, a significant increase in frequencies of loss of chromosome X （9.2± 3.2‰ vs. 1.1 ± 0.9‰, P 〈 0.001） and Y （2.5 ± 1.9‰ vs. 0.2± 0.3‰, P 〈 0.001） was found in old men. Similarly, nondisjunction of chromosome X （16.5± 3.4‰ vs. 3.5 ± 1.1‰, P 〈 0.001） and Y （7.2 ± 2.6‰ vs. 2.4 ± 1.3‰, P 〈 0.001） occurred more frequently in old men than in young men. Regardless of donor＇s age, nondisjunction is more prevalent than loss for both chromosome X and Y. The frequencies of observed simultaneous malsegregation were relatively higher than the expected, suggest- ing an association between malsegregation. These results indicated that in Chinese men, malsegregation of the sex chromosomes increases with age in an associated fashion, and nondisjunction accounts for the majority of spontaneous chromosome malsegregation.

Screening for Y chromosome microdeletions in idiopathic and nonidiopathic infertile men with varicocele and cryptorchidism

Cytogenetic and molecular studies of azoospermic and oligozoospermic males have suggested the presence of azoospermia factors （AZF） in the Y chromosome. Deletion in AZF regions has been reported to disrupt spermatogenesis and cause infertility. Several candidate genes responsible for spermatogenesis have been identified in this region and some of them are thought to be functional in human spermatogenesis. And we reported clinical and molecular studies of Y chromosome microdeletions in Chinese. This study aimed at assessing the frequency of microdeletions in Chinese men with idiopathic and nonidiopathic infertility problems and dicussing the clinical significance of the AZF region.

Roles of the Y chromosome genes in human cancers

Male and female differ genetically by their respective sex chromosome composition, that is, XY as male and XX as female. Although both X and Y chromosomes evolved from the same ancestor pair of autosomes, the Y chromosome harbors male-specific genes, which play pivotal roles in male sex determination, germ cell differentiation, and masculinization of various tissues. Deletions or translocation of the sex-determining gene, SRY, from the Y chromosome causes disorders of sex development （previously termed as an intersex condition） with dysgenic gonads. Failure of gonadal development results not only in infertility, but also in increased risks of germ cell tumor （GCT）, such as gonadoblastoma and various types of testicular GCT. Recent studies demonstrate that either loss of Y chromosome or ectopic expression of Y chromosome genes is closely associated with various male-biased diseases, including selected somatic cancers. These observations suggest that the Y-linked genes are involved in male health and diseases in more frequently than expected. Although only a small number of protein-coding genes are present in the male-specific region of Y chromosome, the impacts of Y chromosome genes on human diseases are still largely unknown, due to lack of in vivo models and differences between the Y chromosomes of human and rodents. In this review, we highlight the involvement of selected Y chromosome genes in cancer development in men.

Convergence of Y Chromosome STR Haplotypes from Different SNP Haplogroups Compromises Accuracy of Haplogroup Prediction

The paternally inherited Y chromosome has been widely used in forensics for personal identification, in anthropology and population genetics to understand origin and migration of human populations, and also in medical and clinical studies （Wang and Li, 2013; Wang et al., 2014）. There are two kinds of extremely useful markers in Y chromosome, single nucle- otide polymorphism （SNP） and short tandem repeats （STRs）. With a very low mutation rate on the order of 3.0 x 10-8 mutations/nucleotide/generation （Xue et al., 2009）, SNP markers have been used in constructing a robust phylogeny tree linking all the Y chromosome lineages from world pop- ulations （Karafet et al., 2008）. Those lineages determined by the pattern of SNPs are called haplogroups. That is to say, we have to genotype an appropriate number of SNPs in order to assign a given Y chromosome to a haplogroup. Compared with SNPs, the mutation rates of STR markers are about four to five orders of magnitude higher （Gusmgo et al., 2005; Ballantyne et al., 2010）. Typing STR has advantages of saving time and cost compared with typing SNPs in phylogenetic assignment of a Y chromosome （Wang et al., 2010）. A set of STR values for an individual is called a haplotype. Because of the disparity in mutation rates between SNP and STR, one SNP haplogroup could actually comprise many STR haplotypes （Wang et al., 2010）. It is most interesting that STR variability is clustered more by haplogroups than by populations （Bosch et al., 1999; Behar et al., 2004）, which indicates that STR haplotypes could be used to infer the haplogroup information of a given Y chromosome. There has been increasing interest in this cost- effective strategy for predicting the haplogroup from a given STR haplotype when SNP data are unavailable. For instance, Vadim Urasin＇s YPredictor （http：//predictor.ydna.ru/）, Whit Atheys＇ haplogroup predictor （http：//www.hprg.com/hapest5/） （Athey, 2005, 2006）, and haplogroup classifier of Arizona University （Schlecht et al., 2008） have been widely employed in previous studies for haplogroup prediction （Larmuseau et al., 2010; Bembea et al., 2011; Larmuseau et al., 2012; Tarlykov et al., 2013）.