Microdeletions In AZF Region Research Articles

Gene Polymorphism, Microdeletion, and Gene Expression of PRM1, PRM2, AZFc in Infertile Males.

Background: Male infertility contributes to roughly 15% of all infertility cases in couples. The most common cause of male infertility is azoospermia, which is caused by genetic mutations. The connection between various single nucleotide polymorphisms in the PRM genes and AZF region microdeletions with male infertility has not been reported. In this case-control study, 100 infertile males (33 with azoospermia, 48 with oligozoospermia, and 19 with severe oligozoospermia) were chosen as the study subjects, and 100 fertile males were selected. Total DNA from peripheral blood was used to amplify two sequence-tagged site markers through multiplex PCR to detect AZFc partial deletions, and SNPs in PRM1 and PRM2 were determined through PCR-RFLP. Furthermore, quantitative real-time PCR was conducted to evaluate PRM1, PRM2, and DAZ1 (found in the AZFc region) expression levels in testis tissue. The frequency of the rs779337774 SNP in the PRM2 gene in the study population had no significant differences. However, a significant association was observed between the rs737008CA genotype (P= 0.013) and the C allele (P= 0.025) as a risk factor for male infant mortality. The deletion of sY254 and sY255 was discovered in azoospermia and severe oligozoospermia patients. Furthermore, all of these genes showed considerably low expression levels. However, only DAZ1 was identified with diagnostic biomarker potential (AUC=0.742). When these genes expression levels are reduced, the likelihood of spermatozoa retrieval in azoospermic individuals is elevated. Furthermore, no significant association was observed between PRM2 polymorphism and azoospermia; however, the CA genotype of PRM1 polymorphism is significantly associated with azoospermia incidence.

AZFa Microdeletions: Occurrence in Chinese Infertile Men and Novel Deletions Revealed by Semiconductor Sequencing

To evaluate the frequency of azoospermia factor (AZFa) microdeletions among infertile men and establish a new high-throughput sequencing method to detect novel deletion types. A total of 3731 infertile men were included. Karyotype analysis was performed using G-band staining of peripheral blood lymphocytes. Polymerase chain reaction (PCR) amplification using specific sequence-tagged sites (STS) was performed to screen for AZF region microdeletions of the Y chromosome. A novel semiconductor sequencing method was established to detect high-resolution AZFa microdeletions. Of 3731 infertile men, 341 (9.14%) had microdeletions in AZFa, AZFb, or AZFc. Thirteen of these (3.81%) had a deletion in the AZFa region (mean age: 27.3 ± 4 years, range: 22-34), which included 12 subjects with a normal karyotype (46, XY) and 1 with Klinefelter syndrome (47, XXY). Four of 10 subjects with complete AZFa microdeletions (sY86 and sY84 loss) underwent semiconductor sequencing. They all had DNA sequence deletions from nt 14469266 to 15195932, whereas their fathers had no deletions. One subject with partial AZFa microdeletion (sY86 loss) and his father underwent semiconductor sequencing and STS-PCR analysis. The same deletion (sY86 loss with DNA sequence deletion from nt 14469266 to 14607672) was identified in both subjects. Forty sperm donators and 50 infertile men showed no AZFa microdeletions by either method. AZFa deletions are present at a low frequency in men with azoospermia or oligozoospermia. Novel sequencing methods can be used for these patients to reveal high-resolution AZFa microdeletions.

Clinical data for 185 infertile Iranian men with Y-chromosome microdeletion

Detection of Y-chromosome microdeletion is useful to obtain reliable genetic information for assisted reproductive techniques, thus avoiding unnecessary treatment and vertical transmission of genetic defects. This research was conducted over a six-year period to analyze clinical data, somatic cytogenetic abnormalities, and types of microdeletions in men with fertility disorders in Iran. A total of 3654 infertile men were included in this study. Semen samples were analyzed according to standard methods. Conventional chromosomal karyotyping was used to analyze chromosome abnormalities. Polymerase chain reaction (PCR) amplification using nine specific sequence-tagged sites (STS) was used to detect AZF microdeletions. Out of the 3654 patients who were analyzed, AZF region microdeletions were detected in 185 cases (5.06 %). Karyotype analysis was available for 157 men and among them abnormal karyotypes were found in 51 cases (32.48 %). One hundred and forty-seven cases with Yq microdeletions suffered from azoospermia and 38 from severe oligozoospermia. Our data show that the most frequent microdeletions were in the AZFc region, followed by the AZFb + c + d, AZFb + c, AZFb, AZFa, and AZF a + c regions. The study has confirmed that the detection of microdeletions in the AZF region is significant from a diagnostic viewpoint. It is also useful to obtain reliable genetic information from infertile men to determine the etiology of the deletions, and to avoid unnecessary treatments and vertical transmission of genetic defects.

The incidence of Y-chromosome microdeletions in Pakistani infertile men

Background: Microdeletions of the azoospermia factor locus of the long arm of Y chromosome are an etiological factor of severe oligozoospermia or azoospermia. Objective: The aim of this study was to investigate the prevalence of Y-chromosome microdeletions in AZF region and their role in infertility in Pakistani population. Materials and Methods: The type of deletions in AZF locus were detected in infertile men (n=113) and the association of Y chromosome microdeletions with male infertility was assessed by including men (50) with normal karyotype and having children. Y chromosome microdeletions were detected by multiplex PCR using 10 sequence tagged sites namely sY81, sY130, sY141, sY142, sY155, sY157, sY160, sY182, sY231, and sY202 that covered all three regions of AZF. Results: Individuals with severe oligozoospermia showed 2.86% deletion frequency in AZFc region as compared to azoospermic males (5.5%). Conclusion: The results of our study showed that deletions in Y chromosome are not playing major part in male infertility. Moreover, multiplex-PCR strategy might preferably be employed for the detection of Y chromosome microdeletions allied to male infertility.

Complex cytogenetic and molecular-genetic analysis of males with spermatogenesis failure

The chromosomal anomalies, microdeletions of AZF region of Y-chromosome and CFTR gene mutations have been studied among 80 infertile men with idiopathic spermatogenetic failure: 36 (45%) patients with aspermia, 19 (24%) patients with azoospermia and 25 (31%) patients with severe oligoasthenoteratozoospermia. In total 30% males with spermatogenetic failure genetic factor of infertility was observed. Karyotype anomalies were observed in 17.5% of infertile men, within 16.2% numerical and structural gonosomal anomalies and in 1.3%--Robertsonian translocation were revealed. In 11% males with spermatogenetic failure, Y-chromosome AZF region microdeletions were detected. The frequency of CFTR major mutation F508del among infertile men was 6.25%. 5T allele of polymorphic locus IVS8polyT was detected in 7.5% of examined men. The results obtained indicate the high complexity of cytogenetic and molecular-genetic studies of male infertility.

Screening for Y chromosome azoospermia factor region microdeletions using modified multiplex PCR

Objective To establish an universal primer-multiplex PCR system for diagnosis of Y chromosome AZF region microdeletions in 262 patients with non-obstructive azoospermic and severe oligozoospermic male infertility. Methods In each panel of multiplex PCR, YUP and YCP containing a fragment of non-human DNA sequence at their 5' ends were designed. The universal primers and chimiric primers were employed for the amplification at the same multiplex PCR system to screen for the Y chromosome AZF region ( a, b and c) microdeletions in 262 non-obstructive azoospermic and severe oligozoospermic male infertility patients. Results Thirty-three out of 262 patients (12. 60% ) were detected with Y chromosome AZF microdeletions. Among them, 27 cases were AZF c microdeletions and 6 ones were AZF b + c microdeletions. These results were in agreement with the results from EMQN method. There was no false-positivity. The gel electrophoresis for detection of multiple STS from both methods showed that the sY84,sY86, sY127, sY134, sY254, sY255, SRY bands were homogeneous and clear with similar brightness. Conclusion The modified multiplex PCR is suitable for screening of Y chromosome AZF microdeletions in non-obstructive azoospermic and severe digozoospermic male infertility patients. Key words: Infertility,male; Y chromosome; Chromosome deletion; Polymerase chain reaction

Chromosomal Abnormality and Y Chromosome Microdeletion in Chinese Patients with Azoospermia or Severe Oligozoo-spermia

Chromosomal abnormality and Y chromosome microdeletion are regarded as two frequent genetic causes associated with spermatogenic failure in Caucasian population. To investigate the distribution of the two genetic defects in Chinese patients with azoospermia or severe oligozoospermia, karyotype analysis by G-banding was carried out in 358 idiopathic infertile men, including 256 patients with azoospermia and 102 patients with severe oligozoospermia, and screening of AZF region microdeletion of Y chromosome by multiplex PCR was performed in those patients without detectable chromosomal abnormality and 100 fertile controls. Of 358 patients, 39(10.9%) were found to have chromosomal abnormalities in which Klinefelters syndrome (47, XXY) was the most common chromosomal aberration. The incidence of sex chromosomal abnormality in patients with azoospermia was significantly higher than that in patients with severe oligozoospermia (12.1% vs 1%). Among the rest of the 319 patients with normal karyotype, 46 (14.4%) were found to have microdeletions in AZF region. The prevalence rates of AZF microdeletion was 15% and 13.1% in patients with azoospermia and severe oligozoospermia respectively. The microdeletion in AZFc was the most frequent deletion and all the microdeletions in AZFa were found in azoospermic patients. No microdeletion in AZF region was detected in fertile controls. In conclusion, chromosomal abnormality and AZF region microdeletion of Y chromosome might account for about 25% of Chinese infertile patients with azoospermia or severe oligozoospermia, suggesting the two abnormalities are important genetic etiology of spematogenic failure in Chinese population and it is essential to screen them during diagnosis of male infertility before in vitro assisted fertilization by introcytoplasmic sperm injection.