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.

AZF microdeletions and partial deletions of AZFc region on the Y chromosome in Moroccan men

Aim： To evaluate for the first time the frequency of Y chromosome microdeletions and the occurrence of the partial deletions of AZFc region in Moroccan men, and to discuss the clinical significance of AZF deletions. Methods： We screened Y chromosome microdeletions and partial deletions of the AZFc region of a consecutive group of infertile men （n = 149） and controls （100 fertile men, 76 normospermic men）. AZFa, AZFb, AZFc and partial deletions of the AZFc region were analyzed by polymerase chain reaction （PCR） according to established protocols. Results： Among the 127 infertile men screened for microdeletion, four subjects were found to have microdeletions： two AZFc deletions and two AZFb＋AZFc deletions. All the deletions were found only in azoospermic subjects （4/48, 8.33%）. The overall AZFc deletion frequency was low （4/127, 3.15%）. AZF microdeletions were not observed in either oligoasthenoteratozoospermia （OATS） or the control. Partial deletions of AZFc （gr/gr） were observed in a total of 7 of the 149 infertile men （4.70%） and 7 partial AZFc deletions （gr/gr） were found in the control group （7/176, 3.98%）. In addition, two b2/b3 deletions were identified in two azoospermic subjects （2/149, 1.34%） but not in the control group. Conclusion： Our results suggest that the frequency of Y chromosome AZF microdeletions is elevated in individuals with severe spermatogenic failure and that gr/gr deletions are not associated with spermatogenic failure.

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.

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.

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）

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）

Y microdeletions in the Istria county,Croatia

Aim:To establish the frequency of Y chromosome microdeletions in an unselected group of infertile Croatian men. Methods:An unselected group of 105 patients (male partners of infertile couples),both with idiopathic and non- idiopathic infertility,consecutively referred to the outpatient infertility clinic,gynecology department,General Hospital Pula,Istria County,Croatia,was examined for the presence or absence of Y chromosome microdeletions by poly- merase chain reaction analysis.Results:One of the 105 men (0.95 %,95 % CI=0.17-5.2 %) was found to have a microdeletion.Conclusion:A low frequency of Y chromosome microdeletions was found in the group of unselected infertile Croatian men.

Molecular study on Y chromosome microdeletions in Egyptian males with idiopathic infertility

Aim: To determine the frequency of genetic deletions within the azoospermia factors in Egyptian infertile males. Methods: The Yq microdeletions in 33 infertile males with undetectable chromosomal anomalies were examined by mutiplex polymerase chain reaction (PCR). Deletions were confirmed using single PCR amplifications. Results: Four out of the total 33 (12 %) men had Yq11 microdeletions, thus supporting the average reported figures in other populations. Three of those 4 cases had single short tandem sequence deletions with discrete histological findings of their testes. Single sY272 deletion within AZFc was associated with Sertoli cell only syndrome, whereas a patient with isolated sY84 deletion within AZFa had immature testicular structure. The remaining case had a large deletion in AZFa-c and short stature. Conclusion: The present study supports the hypothesis that the Yqn encompasses genetic determinants of stature besides genes controlling spermatogenesis.

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.

Implications of Cytogenetic Abnormalities and Azoospermia Factor Microdeletions in Assisted Procreation

Assisted procreation techniques have revolutionized the management of infertility and have offered hope to millions of infertile couples. The main aim of these procedures is to produce healthy offspring. However recent studies on short term outcome of ART have reported a higher incidence of low birth weight, development delay, imprinting defects, sex and autosomal structural abnormalities, major and minor congenital malformation and certain cancers in babies conceived via ART. Further the health of ART conceived children beyond the neonatal period have been less well evaluated. A large number of infertile couples opting for ART have an underlying genetic aetiology. These genetic aberrations are iatrogenitically transmitted via ART. Thus it is important that all couples undergo a detailed and comprehensive genetic evaluation prior to ART.

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.

Microdeletions and vertical transmission of the Y-chromosome azoospermia factor region

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.

Relationship between microdeletion on Y chromosome and patients with idiopathic azoospermia and severe oligozoospermia in the Chinese

Objectives To evaluate the relationship between microdeletion or mutation on the Y chromosome and Chinese patients with idiopathic azoospermia and severe oligozoospermia and to establish a molecular detection method.Methods Microdeletion or mutation detection at the AZFa (sY84 and USP9Y), AZFb, AZFc/DAZ and SRY regions of the Y chromosome. Seventy-three azoospermia and 28 severe oligozoospermia patients were evaluated using PCR and PCR-SSCP techniques.Results Twelve of 101 patients (12%) with the AZFc/DAZ microdeletion were found, including 8 with azoospermia (11%) and 4 with severe oligozoospermia (14.3%), and 1 patient had a AZFb and AZFc/DAZ double deletion. No deletions in the AZFa or SRY regions were found. No deletions in AZFa, AZFb, AZFc/DAZ or SRY regions were found in 60 normal men who had produced one or more children.Conclusions Microdeletion on the Y chromosome, especially at its AZFc/DAZ regions, may be a major cause of azoospermia and severe oligozoospermia leading to male infertility in China. It is recommended that patients have genetic counseling and microdeletion detection on the Y chromosome before intracytoplasmic sperm injection.

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.

Y chromosome microdeletion screening using a new molecular diagnostic method in 1030 Japanese males with infertility

The azoospermia factor(AZF)region is important for spermatogenesis,and deletions within these regions are a common cause of oligozoospermia and azoospermia.Although several studies have reported this cause,the present research,to the best of our knowledge,is the first large-scale study assessing this factor in Japan.In this study,1030 male patients with infertility who were examined for Y chromosome microdeletion using the polymerase chain reaction-reverse sequence-specific oligonucleotide(PCR-rSSO)method,a newly developed method for Y chromosome microdeletion screening,were included.The study enrolled 250 patients with severe oligospermia and 717 patients with azoospermia.Among the 1030 patients,4,4,10,and 52 had AZFa,AZFb,AZFb+c,and AZFc deletions,respectively.The sperm recovery rate(SRR)of microdissection testicular sperm extraction in patients with AZFc deletions was significantly higher than that in those without AZF deletions(60.0%vs 28.7%,P=0.04).In patients with gr/gr deletion,SRR was 18.7%,which was lower than that in those without gr/gr deletion,but was not statistically significant.In conclusion,our study showed that the frequency of Y chromosome microdeletion in male patients in Japan was similar to that reported in patients from other countries,and SRR was higher in patients with AZFc deletion.

Y-chromosome microdeletions in nonobstructive azoospermia and severe oligozoospermia

The aim of the present work was to present the outcomes of the patients with Y-chromosome microdeletions treated by intracytoplasmic sperm injection （ICSI）, either using fresh （TESE） or frozen-thawed （TESE-C） testicular sperm and ejaculated sperm （EJAC）. The originality of this work resides in the comparisons between the different types of Y-microdeletions （AZFa, AZFb, and AZFc） and treatments, with detailed demographic, stimulation, embryological, clinical, and newborn （NB） outcomes. Of 125 patients with Y-microdeletions, 33 patients presented severe oligozoospermia （18 performed ICSI with ejaculated sperm） and 92 secretory azoospermia （65 went for TESE with 40 having successful sperm retrieval and performed ICSI）. There were 51 TESE treatment cycles and 43 TESE-C treatment cycles, with a birth of 19 NB （2 in AZFa/TESE-C, 12 in AZFc/TESE, and 5 in AZFc/TESE-C）. Of the 29 EJAC cycles, there was a birth of 8 NB （in AZFc）. In TESE and EJAC cycles, there were no significant differences in embryological and clinical parameters. In TESE-C cycles, there was a significant lower oocyte maturity rate, embryo cleavage rate and mean number of embryos transferred in AZFb, and a higher mean number of oocytes and lower fertilization rate in AZFc. In conclusion, although patients with AZFc microdeletions presented a high testicular sperm recovery rate and acceptable clinical outcomes, cases with AZFa and AZFb microdeletions presented a poor prognosis. Due to the reported heredity of microdeletions, patients should be informed about the infertile consequences on NB and the possibility of using preimplantation genetic diagnosis for female sex selection.

Reproductive outcomes of intracytoplasmic sperm injection using testicular sperm and ejaculated sperm in patients with AZFc microdeletions:a systematic review and meta-analysis

Studies have explored the assisted reproductive technology(ART)outcomes of Y-chromosome azoospermia factor c(AZFc)microdeletions,but the effect of sperm source on intracytoplasmic sperm injection(ICSI)remains unknown.To determine the ART results of ICSI using testicular sperm and ejaculated sperm from males with AZFc microdeletions,we searched Embase,Web of Science,and PubMed to conduct a systematic review and meta-analysis.The first meta-analysis results for 106 cycles in five studies showed no significant differences in the live birth rate between the testicular sperm group and the ejaculated sperm group(risk ratio:0.97,95%confidence interval[CI]:0.73-1.28,P=0.82).The second meta-analysis of 106 cycles in five studies showed no difference in the abortion rate between the testicular sperm group and ejaculated sperm group(risk ratio:1.06,95%Cl:0.54-2.06,P=0.87).The third meta-analysis of 386 cycles in seven studies showed no significant difference in clinical pregnancy rates between the testicular sperm group and the ejaculated sperm group(risk ratio:1.24,95%Cl:0.66-2.34,P=0.50).Inevitable heterogeneity weakened our results.However,our results indicated that testicular sperm and ejaculated sperm yield similar ART outcomes,representing a meaningful result for clinical treatment.More properly designed studies are needed to further confirm our conclusions.

Use of amniocytes for prenatal diagnosis of 22q11.2 microdeletion syndrome： a feasibility study

Background A study of prenatal genetic diagnosis for 22q11.2 microdeletion, which has a wide phenotypic spectrum that involves almost all organs, is rarely reported in China. This study aimed to explore the prevalence of 22q11.2 microdeletion in congenitally malformed fetuses via the fluorescent in situ hybridization （FISH） technique and to investigate the feasibility of use of amniocytes to diagnose 22q11 .2 microdeletion syndrome prenatally. Methods The study enrolled 23 cases of fetal cardiac malformation, as indicated by ultrasound in Beijing Anzhen Hospital and 14 cases of non-cardiac malformation, as determined by type-B ultrasound in Beijing Anzhen Hospital and other hospitals. Amniotic fluid was obtained by amniocentesis before odinopoeia, and the stillborn fetuses of the induced labor were preceded to autopsy. The amniotic fluid of 20 cesarean deliveries during the same period of time was used as a control. The TUPLE1 gene in the amniotic fluid of malformed and normal fetuses was assessed by the FISH method. Results The prevalence rates of the TUPLE1 gene deletion in the amniotic fluid cells from fetuses with cardiac deformations and fetuses without such malformations were 43.5% and 57.1%, respectively. The deletion of TUPLE1 was significantly associated with fetal malformation. Conclusion Chromosome 22q11.2 microdeletion is one of the major factors leading to fetal congenital malformations, and prenatal FISH screening for 22q11 .2 microdeletion syndrome is technically feasible using amniocytes.

Syndromic craniosynostosis associated with microdeletion of chromosome 19p13.12-19p13.2

Craniosynostosis,a condition in which the cranial sutures prematurely fuse,can lead to elevated intracranial pressure and craniofacial abnormalities in young children.Currently surgical intervention is the only therapeutic option for patients with this condition.Craniosynostosis has been associated with a variety of different gene mutations and chromosome anomalies.Here we describe three cases of partial deletion of chromosome 19p.Two of the cases present with syndromic craniosynostosis while one has metopic ridging.A review of the genes involved in the rearrangements between the three cases suggests several gene candidates for craniosynostosis.CALR and DAND5,BMP regulators involved in osteoblast differentiation,and MORG1,a mediator of osteoclast dysregulation may play a role in abnormal cranial vault development.Additionally,CACNA1A,a gene that when mutated is associated with epilepsy and CC2D1A,a gene associated with non-syndromic mental retardation may contribute to additional phenotypic features seen in the patients we describe.In addition,these findings further support the need for genetic testing in cases of syndromic craniosynostosis.

Chromosomal disorders and male infertility

Infertility in humans is surprisingly common occurring in approximately 15% of the population wishing to start a family. Despite this, the molecular and genetic factors underlying the cause of infertility remain largely undiscovered. Nevertheless, more and more genetic factors associated with infertility are being identified. This review will focus on our current understanding of the chromosomal basis of male infertility specifically： chromosomal aneuploidy, structural and numerical karyotype abnormalities and Y chromosomal microdeletions. Chromosomal aneuploidy is the leading cause of pregnancy loss and developmental disabilities in humans. Aneuploidy is predominantly maternal in origin, but concerns have been raised regarding the safety of intracytoplasmic sperm injection as infertile men have significantly higher levels of sperm aneuploidy compared to their fertile counterparts. Males with numerical or structural karyotype abnormalities are also at an increased risk of producing aneuploid sperm. Our current understanding of how sperm aneuploidy translates to embryo aneuploidy will be reviewed, as well as the application of preimplantation genetic diagnosis （PGD） in such cases. Clinical recommendations where possible will be made, as well as discussion of the use of emerging array technology in PGD and its potential applications in male infertility.