Evaluation of chromosomal abnormalities and Y-chromosome microdeletions in 1696 Turkish cases with primary male infertility: A single-center study

A retrospective analysis of 1600 infertility patients with azoospermia and severe oligozoospermia

OBJECTIVE

This study aimed to investigate the genetic etiology of male infertility patients.

METHOD

A total of 1600 male patients with infertility, including 1300 cases of azoospermia and 300 cases of severe oligozoospermia, underwent routine semen analysis, chromosomal karyotype analysis and sex hormone level testing. The Azoospermia factor (AZF) on the Y chromosome was detected using the multiple fluorescence quantitative PCR technique. Additionally, copy number variation (CNV) analysis was performed on patients with Sertoli-cell-only syndrome who had a normal karyotype and AZF.

RESULT

Chromosomal abnormalities were found in 334 cases (20.88 %) of the 1600 male infertility patients. The most common type of abnormality was sex chromosome abnormalities (18.94 %), with 47, XXY being the most frequent abnormal karyotype. The rates of chromosomal abnormalities were significantly different between the azoospermia group and the severe oligospermia group (23.69 % and 8.67 %, respectively; P<0.05). AZF microdeletions were detected in 155 cases (9.69 %), with various deletion types and AZFc region microdeletion being the most prevalent. The rates of AZF microdeletions were not significantly different between the azoospermia group and the severe oligospermia group (9.15 % and 12 %, respectively; P=0.133). In 92 patients with Sertoli-cell-only syndrome who had a normal karyotype and AZF, the detection rate of CNV was 16.3 %. Compared to the severe oligospermia group, the azoospermia group had higher levels of FSH and LH and lower levels of T and E2, and the differences were statistically significant (P<0.05).

CONCLUSIONS

Male infertility is a complex multifactorial disease, with chromosomal abnormalities and Y chromosome microdeletions being important genetic factors leading to the disease. Initial genetic testing of infertile men should include karyotyping and Y chromosome microdeletions. If necessary, CNV testing should be performed to establish a clinical diagnosis and provide individualized treatment for male infertility.

A New Sperm Concentration Threshold for Y Chromosome Microdeletion Analysis in Infertile Men: Could It Be Azoopermia?

Objective

We aimed to assess the frequency of Y-chromosome microdeletions (YCMs) in a non-multiethnic urban population in our region, define predictive factors, and determine a new clinical threshold for YCMs in infertile men.

Materials and Methods

A total of 281 patients with a sperm concentration ≤5 million/mL were retrospectively evaluated. Oligozoospermic and/or azoospermic patients with a sperm concentration of ≤5 million/mL were screened for the YCM analysis.

Results

Y-chromosome microdeletion was detected in 9 (3.2%) of the 281 patients. All patients with YCM were azoospermic. The presence of azoospermia, a high folliclestimulating hormone level, and a high luteinizing hormone level were found to be important determinants for the identification of a microdeletion (P = .002, P = .002, and P=.021, respectively). If the presence of azoospermia and a sperm concentration threshold of <1 million/mL had been applied for the YCM test, the number of tests performed would have been reduced by 54.4% (153 tests) and 42.7% (120 tests), respectively, resulting in cost saving of approximately $11 474 and $9000, respectively.

Conclusion

We recommend that the threshold for sperm concentration for YCM analysis be set at <1 million in individuals in developed countries and only in patients with azoospermia in developing countries, in order to reduce costs and save labor by excluding unnecessary tests. These proposed thresholds (azoospermia and sperm counts less than <1 million/mL) provide cost-effectiveness by significantly reducing the number of genetic tests ordered without affecting the diagnosis rate.

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

Background

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.

Methods

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.

Results

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).

Conclusion

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.

Indication for Y Chromosome Microdeletion Analysis in Infertile Men: Is a New Sperm Concentration Threshold Needed?

OBJECTIVE

To describe the prevalence of Y-chromosome deletions in patients with a sperm concentration of less than 5 million/mL. To also determine a new sperm threshold for Y-chromosome analysis in men with infertility.

METHODS

A total of 3023 patients who had a semen concentration of less than 5 million/mL included in this retrospective study. All of these patients had a genetic evaluation, hormonal evaluation, and 2 abnormal semen analyses.

RESULTS

Y-chromosome deletions were present in 116 (3.8 %) patients with sperm concentration <5 million/mL. The frequency of a Y-chromosome deletions was 6.8%, 1.0%, 0.15% in azoospermic men, in men with sperm concentrations of 0-1 million /mL, in men with sperm concentrations of 1-5 million/mL. Patients were divided into 2 groups regarding the determined new sperm threshold. The sensitivity and specificity of the Y-chromosome deletions test were 92.2.7% and 49.3 %, 99.1%, and 22.1% in patients with azoospermia and sperm concentrations <1 million/mL, respectively. If the sperm concentration thresholds of azoospermia or <1 million/mL, are applied, the number of tests decreased to 50.5% (1442 tests) and 23.1% (643 tests), respectively. Approximately $108,150 and $48,225 would be saved if the sperm thresholds were azoospermia and <1 million/mL, respectively CONCLUSION: The current threshold of sperm concentration for Y-chromosome deletions is controversial. The new proposed sperm threshold for genetic testing of 1 million/mL would increase sensitivity and more cost-effective compared to the current threshold.