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.

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.

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.

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.

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.

Evaluation of the azoospermic male

When presented with an azoospermic patient, a thorough history and careful, considered physical examination often leads to a definite or presumptive diagnosis. An algorithmic, logical thought process is important to have in mind when embarking on the evaluation. Adjunctive laboratory tests, such as hormonal assays or genetic studies, are often complementary and/or additive and allow a very precise determination to be made as to the etiologies, either genetic or acquired. It is only with this information that a therapeutic plan can be made for the patient. As will be discussed, a targeted approach to testing is far more satisfying and cost-effective than a blind, shotgun approach.

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.

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.

The association between the two more common genetic causes of spermatogenic failure:a 7-year retrospective study

Chromosomal abnormalities and Y chromosome microdeletions are considered to be the two more common genetic causes of spermatogenic failure.However,the relati on ship between chromosomal aberrations and Y chromosome microdeletio ns is still un clear.This study was to investigate the incidenee and characteristics of chromosomal aberrations and Y chromosome microdeletions in infertile men,and to explore whether there was a correlation between the two genetic defects of spermatogenic failure.A 7-year retrospective study was conducted on 5465 infertile men with nonobstructive azoospermia or oligozoospermia.Karyotype analysis of peripheral blood lymphocytes was performed by standard G-banding techniques.Y chromosome microdeletions were screened by multiplex PCR amplification with six specific sequence-tagged site(STS)markers.Among the 5465 infertile men analyzed,371(6.8%)had Y chromosome microdeletions and the prevalence of microdeletions in azoospermia was 10.5%(259/2474)and in severe oligozoospermia was 6.3%(107/1705).A total of 4003(73.2%)infertile men underwent karyotyping;370(9.2%)had chromosomal abnormalities and 222(5.5%)had chromosomal polymorphisms.Karyotype analysis was performed on 272(73.3%)patients with Y chromosome microdeletions and 77(28.3%)had chromosomal aberrations,all of which involved sex chromosomes but not autosomes.There was a sign ifica nt d iff ere nee in the frequency of chromosomal abno rmalities betwee n men with and without Y chromosome microdeletions(P<0.05).