Genetic Causes Of Male Infertility Research Articles

Klinefelter syndrome in a patient with double Y-autosomal translocation

Klinefelter syndrome is one of the most common chromosomal abnormalities and the most common genetic cause of male infertility. About 85 % of patients have 47,XXY karyotype, other patients have other non-mosaic and mosaic Klinefelter syndrome variants. We report a unique clinical case — Klinefelter syndrome patient with double Y autosomal translocation. The proband is a 15-year-old male patient (height 180 cm, weight 50 kg, normal IQ) who was admitted for cytogenetic examination and genetic counseling due to delayed puberty. He was diagnosed with testicular hypoplasia, hypergonadotropic hypogonadism, pituitary microadenoma and left-sided varicocele. The proband was born in a nonconsanguineous marriage after in vitro fertilization due to paternal male factor infertility. Cytogenetic analysis was performed on cultured peripheral blood lymphocytes using standard chromosome analysis with GTG staining and FISH analysis. Molecular analysis of the Y chromosome was performed by multiplex PCR. Complex cytogenetic examination revealed a 46,XX,der(Y) t(Y;15)(q12;q11.1),der(13)t(Y;13)(q12;p11.2),-15 karyotype in the proband. Molecular analysis showed that the proband is SRY positive; no microdeletion of the Y chromosome was found. The detected double Y autosomal translocation is a chromosomal abnormality independent of KS. The father of the proband is an oligozoospermic man with robertsonian translocation 13;15 — 45,XY,der(13;15)(q10;q10), the mother has a normal karyotype 46,XX. Apparently, the der(13) and der(Y) chromosomes result from abnormal meiotic recombination in paternal meiosis between the heterochromatic region Yq12 and the centromeric/pericentromeric heterochromatin of chromosomes 13 and 15 involved in the paternal robertsonian translocation, and Klinefelter syndrome is due to the presence of two X chromosomes in the karyotype in the presence of a derivative Y chromosome. The detected double Y-autosomal translocation is a chromosomal abnormality unrelated to Klinefelter syndrome, arising on the background of the paternal robertsonian translocation.

Innovative all-in-one exome sequencing strategy for diagnostic genetic testing in male infertility: Validation and 10-month experience.

Current guidelines indicate that patients with extreme oligozoospermia or azoospermia should be tested for chromosomal imbalances, azoospermia factor (AZF) deletions and/or CFTR variants. For other sperm abnormalities, no genetic diagnostics are recommended. To determine whether exome sequencing (ES) with combined copy number variant (CNV) and single nucleotide variant (SNV) analysis is a reliable first-tier method to replace current methods (validation study), and to evaluate the diagnostic yield after 10 months of implementation (evaluation study). In the validation study, ES was performed on DNA of patients already diagnosed with AZF deletions (n=17), (non-)mosaic sex chromosomal aneuploidies or structural chromosomal anomalies (n=37), CFTR variants (n=26), or variants in known infertility genes (n=4), and 90 controls. The data were analyzed using our standard diagnostic pipeline, with a bioinformatic filter for 130 male infertility genes. In the evaluation study, results of 292 clinical exomes were included. All previously reported variants in the validation cohort, including clinically relevant Y-chromosomal microdeletions, were correctly identified and reliably detected. In the evaluation study, we identified one or more clinically relevant genetic anomalies in 67 of 292 of all cases (22.9%): these included aberrations that could have been detected with current methods in 30 of 67 patients (10.2% of total), (possible) (mono)genetic causes in the male infertility gene panel in 28 of 67 patients (9.6%), and carriership of cystic fibrosis in nine of 67 patients (3.1%). ES is a reliable first-tier method to detect the most common genetic causes of male infertility and, as additional genetic causes can be detected, in our evaluation cohort the diagnostic yield almost doubled (10.2%-19.8%, excluding CF carriers). A genetic diagnosis provides answers on the cause of infertility and helps the professionals in the counseling for treatment, possible co-morbidities and risk for offspring and/or family members. Karyotyping will still remain necessary for detecting balanced translocations or low-grade chromosomal mosaicism.

A Novel Compound Heterozygous Mutation in TDRD9 Causes Oligozoospermia

Oligozoospermia is an important cause of male infertility for which treatment options are limited. Spermatogenesis is complex, and the causes of oligozoospermia remain largely unknown. Because genetic mutations are important factors of oligozoospermia pathogenesis, our study aimed to explore the genetic causes of oligozoospermia. Whole- exome sequencing (WES) was performed on one proband from a Chinese family who was diagnosed with oligozoospermia. The pathogenic mutations were confirmed by Sanger sequencing, and a minigene assay was used to determine the effect of the identified splicing mutation. We identified a novel compound heterozygous mutation in the TDRD9 gene, comprising a splicing mutation (c.1115 + 3A > G) and a frameshift mutation (c.958delC), in the proband; neither of these mutations were found in 50 unrelated healthy people. In addition, a minigene assay demonstrated that the frameshift produced partially truncated protein, and the splicing mutation led to a frameshift mutation and premature termination due to abnormal alternative splicing of TDRD9. These findings indicate that deleterious compound heterozygous mutation in TDRD9 could lead to oligozoospermia, highlighting the crucial role of TDRD9 in spermatogenesis and further clarifying the genetic causes of male infertility resulting from oligozoospermia. Our study expands the spectrum of TDRD9-related phenotypes and provides a new specific target for future genetic counseling.

A novel homozygous missense TTC12 variant identified in an infertile Pakistani man with severe oligoasthenoteratozoospermia and primary ciliary dyskinesia.

TTC12 is a cytoplasmic and centromere-localized protein that plays a role in the proper assembly of dynein arm complexes in motile cilia in both respiratory cells and sperm flagella. This finding underscores its significance in cellular motility and function. However, the wide role of TTC12 in human spermatogenesis-associated primary ciliary dyskinesia (PCD) still needs to be elucidated. Whole-exome sequencing (WES) and Sanger sequencing were performed to identify potentially pathogenic variants causing PCD and multiple morphological abnormalities of sperm flagella (MMAF) in an infertile Pakistani man. Diagnostic imaging techniques were used for PCD screening in the patient. Real-time polymerase chain reaction (RT‒PCR) was performed to detect the effect of mutations on the mRNA abundance of the affected genes. Papanicolaou staining and scanning electron microscopy (SEM) were carried out to examine sperm morphology. Transmission electron microscopy (TEM) was performed to examine the ultrastructure of the sperm flagella, and the results were confirmed by immunofluorescence staining. Using WES and Sanger sequencing, a novel homozygous missense variant (c.C1069T; p.Arg357Trp) in TTC12 was identified in a patient from a consanguineous family. A computed tomography scan of the paranasal sinuses confirmed the symptoms of the PCD. RT-PCR showed a decrease in TTC12 mRNA in the patient's sperm sample. Papanicolaou staining, SEM, and TEM analysis revealed a significant change in shape and a disorganized axonemal structure in the sperm flagella of the patient. Immunostaining assays revealed that TTC12 is distributed throughout the flagella and is predominantly concentrated in the midpiece in normal spermatozoa. In contrast, spermatozoa from patient deficient in TTC12 showed minimal staining intensity for TTC12 or DNAH17 (outer dynein arms components). This could lead to MMAF and result in male infertility. This novel TTC12 variant not only illuminates the underlying genetic causes of male infertility but also paves the way for potential treatments targeting these genetic factors. This study represents a significant advancement in understanding the genetic basis of PCD-related infertility.

An analysis of Y-chromosome microdeletion in infertile Korean men with severe oligozoospermia or azoospermia.

Infertility affects 10% to 15% of couples, and male factor accounts for 50% of the cases. The relevant male genetic factors, which account for at least 15% of male infertility, include Y-chromosome microdeletions. We investigated clinical data and patterns of Y-chromosome microdeletions in Korean infertile men. A total of 919 infertile men whose sperm concentration was ≤5 million/mL in two consecutive analyses were investigated for Y-chromosome microdeletion. Among them, 130 infertile men (14.1%) demonstrated Y-chromosome microdeletions. Medical records were retrospectively reviewed. In 130 men with Y-chromosome microdeletions, 90 (69.2%) had azoospermia and 40 (30.8%) had severe oligozoospermia. The most frequent microdeletions were in the azoospermia factor (AZF) c region (77/130, 59.2%), followed by the AZFb+c (30/130, 23.1%), AZFa (8/130, 6.2%), AZFb (7/130, 5.4%), AZFa+b+c (7/130, 5.4%), and AZFa+c (1/130, 0.7%) regions. In men with oligozoospermia, 37 (92.5%) had AZFc microdeletion. Chromosomal abnormalities were detected in 30 patients (23.1%). Higher follicle-stimulating hormone level (23.2±13.5 IU/L vs. 15.1±9.0 IU/L, p<0.001), higher luteinizing hormone level (9.7±4.6 IU/L vs. 6.0±2.2 IU/L, p<0.001), and lower testis volume (10.6±4.8 mL vs. 13.3±3.8 mL, p<0.001) were observed in azoospermia patients compared to severe oligozoospermia patients. Y-chromosome microdeletion is a common genetic cause of male infertility. Therefore, Y-chromosome microdeletion test is recommended for the accurate diagnosis of men with azoospermia or severe oligozoospermia. Appropriate genetic counseling is mandatory before the use of assisted reproduction technique in men with Y-chromosome microdeletion.

Unveiling the Genetic Complexity of Teratozoospermia: Integrated Genomic Analysis Reveals Novel Insights into lncRNAs' Role in Male Infertility.

Male infertility is a global health issue, affecting over 20 million men worldwide. Genetic factors are crucial in various male infertility forms, including teratozoospermia. Nonetheless, the genetic causes of male infertility remain largely unexplored. In this study, we employed whole-genome sequencing and RNA expression analysis to detect differentially expressed (DE) long-noncoding RNAs (lncRNAs) in teratozoospermia, along with mutations that are exclusive to teratozoospermic individuals within these DE lncRNAs regions. Bioinformatic tools were used to assess variants' impact on lncRNA structure, function, and lncRNA-miRNA interactions. Our analysis identified 1166 unique mutations in teratozoospermic men within DE lncRNAs, distinguishing them from normozoospermic men. Among these, 64 variants in 23 lncRNAs showed potential regulatory roles, 7 variants affected 4 lncRNA structures, while 37 variants in 17 lncRNAs caused miRNA target loss or gain. Pathway Enrichment and Gene Ontology analyses of the genes targeted by the affected miRNAs revealed dysregulated pathways in teratozoospermia and a link between male infertility and cancer. This study lists novel variants and lncRNAs associated for the first time with teratozoospermia. These findings pave the way for future studies aiming to enhance diagnosis and therapy in the field of male infertility.

Male fertility: a summary overview of the publications October 2022 – March 2023

The article presents an overview of the most significant publications on the topic of male infertility. The main selection criteria were the practical significance of the article, as well as the impact factor of the journal in which it was published, according to the SCImago Journal Rank (SJR). As a result, a list of 10 works published from October 2022 to March 2023 was formed. The review includes articles on the following topics: genetic causes of male infertility, the role of oxidative stress in assisted reproductive technologies (ART) programmes, reference values when performing scrotum and prostate ultrasound, the impact of ART procedures on child development, the impact of DNA fragmentation of spermatozoa on the outcomes of ART, the role of circadian rhythms in spermatogenesis, automated semen testing devices and predictors of success / failure of testicular biopsy.

Infertility treatment for patients having a microdeletion of azoospermic factor (AZF).

In genetic causes of male infertility, Y chromosome microdeletions are the second most common after Klinefelter's syndrome. Although sperm recovery rate is relatively high for subjects with azoospermic factor (AZF) c chromosome microdeletion, intracytoplasmic sperm injection (ICSI) results using retrieved sperm has been reported to be poor. We retrospectively examined the infertility treatment for subjects with AZF microdeletion. From October 2017 to September 2020, chromosomal examination of 67 azoospermic subjects and 12 cryptozoospermia were performed. Of these, twenty-three subjects (29.1%) had AZF microdeletion. Twelve subjects with AZFc microdeletion and one subtype with unknown classification (Ym-9; P3 deletion) received sperm retrieval surgery due to azoospermia. Two subjects obtained motile sperm by microscopic epididymal sperm aspiration (MESA) and four subjects by microscopic testicular sperm extraction (micro-TESE). Pregnancy and healthy delivery were achieved in 6 of 14 subject (42.9%; including one twin) using ICSI. This was comparable with previous reports. Since there were two cases of obstructive azoospermia, we employed MESA to avoid testicular damage. Following observation of the testis and epididymis under operative microscope, a decision was made to perform sperm retrieval surgery to avoid unnecessary testicular damage. Furthermore, since AZFc microdeletion is passed to the next generation, long term follow-up is necessary.

Chromosomal Abnormalities in Infertile Greek Men: A Single Institution’s Experience

Chromosomal abnormalities represent a significant genetic cause of male infertility because they impair spermatogenesis. The objective of the current study was to determine the prevalence and distribution of chromosomal abnormalities in Greek men with infertility. Four hundred eighty-eight infertile men (27 azoospermic, 168 with oligospermia -98 mild, 57 moderate, 13 severe- and 293 with normospermia) undergoing In &lt;em&gt;Vitro &lt;/em&gt;Fertilization (IVF) between 2016-2022 were enrolled in the study. Thirty-eight fertile men were also studied. Chromosomal analysis of peripheral blood lymphocytes was performed using standard cytogenetic techniques. 21/488 (4.3%) of men tested had an abnormal karyotype; 13 (2.7%) had sex chromosome abnormalities and 8 (1.6%) had autosomal ones. No chromosomal aberration was detected in the control group. The frequency of chromosomal alterations was significantly higher in azoospermic men than in men with oligospermia and normospermia (37% vs 4.2% and 1.4% respectively, p &lt; 0.05). Moreover, in men with oligospermia, cytogenetic abnormalities were more common in the severe group (7.7%) followed by the moderate (5.25%) and the mild group (3%). The results of the study are by the literature. Karyotyping is suggestive especially in oligospermic /azoospermic men and before proceeding to IVF. The advent of high throughput sequencing technologies and genome-wide association studies will contribute to discovering novel promising genetic factors involved in male infertility.

AZF gene microdeletions in azoospermic–oligozoospermic males

Background and objectiveThe presence of microdeletions in the Y-chromosome azoospermia factor (AZF) region (YCMs) is considered the most frequent genetic cause of male infertility along with Klinefelter syndrome. The objective of this study was to investigate the frequencies and type of YCMs in infertile men in Aragon and to analyze the relationship between sex hormones, sperm count and microdeletions in them. Patients and methodsRetrospective descriptive study of 644 men who during 2006–2019 were screened for YCMs using YChromStrip (Operón, Spain) by PCR + reverse hybridization, spermiogram, karyotype and quantification of sex hormones. ResultsThe frequency of YCMs was 3.88% (25/644), not being detected in any patient with mild or normospermic oligozoospermia, that is, in sperm counts higher than 5 × 106/mL. The group of azoospermic patients was the one that presented a higher frequency of YCMs (14.58%, 14/96). Deletions in the AZFc region were the most frequent (68%). 20% (5/25) of patients with YCMs also presented some type of karyotype abnormality that included aneuploidies, deletions, duplications and/or translocations. Sperm count was significantly lower and FSH and LH concentrations significantly higher in the group of patients with YCMs. ConclusionsYCMs screening is a key test in the diagnostic approach to male infertility. Obtaining an adequate result allows choosing suitable assisted reproduction techniques, preventing unnecessary treatments and the transmission of genetic defects to offspring.

Gene differential co-expression analysis of male infertility patients based on statistical and machine learning methods.

Male infertility has always been one of the important factors affecting the infertility of couples of gestational age. The reasons that affect male infertility includes living habits, hereditary factors, etc. Identifying the genetic causes of male infertility can help us understand the biology of male infertility, as well as the diagnosis of genetic testing and the determination of clinical treatment options. While current research has made significant progress in the genes that cause sperm defects in men, genetic studies of sperm content defects are still lacking. This article is based on a dataset of gene expression data on the X chromosome in patients with azoospermia, mild and severe oligospermia. Due to the difference in the degree of disease between patients and the possible difference in genetic causes, common classical clustering methods such as k-means, hierarchical clustering, etc. cannot effectively identify samples (realize simultaneous clustering of samples and features). In this paper, we use machine learning and various statistical methods such as hypergeometric distribution, Gibbs sampling, Fisher test, etc. and genes the interaction network for cluster analysis of gene expression data of male infertility patients has certain advantages compared with existing methods. The cluster results were identified by differential co-expression analysis of gene expression data in male infertility patients, and the model recognition clusters were analyzed by multiple gene enrichment methods, showing different degrees of enrichment in various enzyme activities, cancer, virus-related, ATP and ADP production, and other pathways. At the same time, as this paper is an unsupervised analysis of genetic factors of male infertility patients, we constructed a simulated data set, in which the clustering results have been determined, which can be used to measure the effect of discriminant model recognition. Through comparison, it finds that the proposed model has a better identification effect.

A novel loss-of-function variant in PNLDC1 inducing oligo-astheno-teratozoospermia and male infertility.

Male infertility is a major reproductive disorder, which is clinically characterized by highly heterogeneous phenotypes of abnormal sperm count or quality. To date, five male patients with biallelic loss-of-function (LOF) variants of PARN-like ribonuclease domain-containing exonuclease 1 ( PNLDC1 ) have been reported to experience infertility with nonobstructive azoospermia. The aim of this study was to identify the genetic cause of male infertility with oligo-astheno-teratozoospermia (OAT) in a patient from a Chinese Han family. Whole-exome and Sanger sequencing analyses identified a homozygous LOF variant (NM_173516.2, c.142C>T, p.Gln48Ter) in PNLDC1 . Hematoxylin and eosin staining revealed that the spermatozoa of the patient with OAT had an irregular head phenotype, including microcephaly, head tapering, and globozoospermia. Consistently, peanut agglutinin staining of the spermatozoa revealed a complete or partial loss of the acrosome. Furthermore, the disomy rate of chromosomes in the patient's spermatozoa was significantly increased compared with that of a fertile control sample. We reported an LOF variant of the PNLDC1 gene responsible for OAT.

Türk İnfertil Erkeklerde Y kromozomu Mikrodelesyonlarının Sıklığı: Tek Merkez Deneyimi

Objective: Infertility is defined as the failure to achieve a clinical pregnancy after twelve months of regular unprotected sexual intercourse. Both genetic and environmental factors affect infertility. The aim of the study is to establish the frequency of the Y chromosome microdeletions in Turkish infertile men who were referred to our center (2016-2020) with severe oligozoospermia and azoospermia.&#x0D; Methods: A retrospective chart review study on patients who referred to our center between 2016-2020 due to infertility were included in the study. We evaluated microdeletions of the Y-chromosome STS markers AZFa, AZFb and AZFc, ZFX/ZFY, and terminal sY160 regions. Y-chromosome STS markers were evaluated by DNA fragment analysis. &#x0D; Results: The chart review indicated that a total of 319 men applied to our genetic diagnosis center between 2016 and 2020 due to infertility (mean age 32 ±7). Among the 319 infertile men, we determined 21 cases with Y chromosome microdeletions (6.89%), with the most common AZFc deletion (n=11, 52.3%) which is consistent with literature.&#x0D; Conclusion: Y-microdeletions are among the most common genetic causes of male infertility. In azoospermic and oligospermic patients, cytogenetic tests, Y-chromosome microdeletions and NGS panel screening tests can give effective information before the use of assisted reproductive techniques.

Erkek İnfertilitesinin Genetik Nedenlerine Güncel Yaklaşım ve Genetik Danışmanlık

Generally, infertility is defined as the inability of couples who have had unprotected and regular intercourse for at least 12 months or longer to conceive naturally. When all societies in the world are examined, infertility is an important health problem affecting approximately 48 million couples, and it also has socio-cultural, economic, and psychological effects. While 8-12% of reproductive age couples have infertility problems, when gender-related reasons are examined, 20-30% of these reasons are male, 20-30% are female, and 25-40% are together with couples. While the etiology of 60% of male infertility causes has not been clarified yet, congenital urogenital anomalies are the most common causes, and genetic causes are the second most common cause among the known causes. While investigating genetic etiology in patients, chromosomal anomalies and Y microdeletions are at the forefront; however, the importance of monogenic causes has increased as some known genes have been associated with infertility because of familial segregation studies and the whole exome analyses with the development of new generation sequencing technologies. In this review, genetic causes of male infertility, diagnosis, and treatment approaches for genetic causes were examined by the current literature, and the importance of providing the proper genetic counseling to infertility patients was mentioned.

INCIDENCE OF Y CHROMOSOME MICRODELETIONS AND MICRODISSECTION TESTICULAR SPERM EXTRACTION (MICRO TESE) IN JAPANESE AZOOSPERMIC PATIENTS

After Klinefelter syndrome, Y chromosome microdeletions are the second most frequent genetic cause of male infertility, with a prevalence of 2%-10% in non-obstructive azoospermia (NOA) and three spermatogenesis loci in the Y chromosome long arm (Yq11) have been classified as AZFa, AZFb, and AZFc. The classical correlation of histopathology phenotypes with these three microdeletions comprises of complete absence of germ cells (Sertoli cell-only syndrome) in patients with AZFa microdeletions, maturation arrest of meiosis in patients with AZFb microdeletions, and hypospermatogenesis in patients with AZFc microdeletions, however, individual variation in the extent of deletions has led to various spermatogenic phenotypes.

Microdeleciones del gen AZF en varones azoospérmicos-oligozoospérmicos

Background and objectiveThe presence of microdeletions in the Y-chromosome azoospermia factor (AZF) region (YCMs) is considered the most frequent genetic cause of male infertility along with Klinefelter syndrome. The objective of this study was to investigate the frequencies and type of YCMs in infertile men in Aragon and to analyze the relationship between sex hormones, sperm count and microdeletions in them. Patients and methodsRetrospective descriptive study of 644 men who during 2006–2019 were screened for YCMs using YChromStrip (Operón, Spain) by PCR+reverse hybridization, spermiogram, karyotype and quantification of sex hormones. ResultsThe frequency of YCMs was 3.88% (25/644), not being detected in any patient with mild or normospermic oligozoospermia, that is, in sperm counts higher than 5×106/mL. The group of azoospermic patients was the one that presented a higher frequency of YCMs (14.58%, 14/96). Deletions in the AZFc region were the most frequent (68%). 20% (5/25) of patients with YCMs also presented some type of karyotype abnormality that included aneuploidies, deletions, duplications and/or translocations. Sperm count was significantly lower and FSH and LH concentrations significantly higher in the group of patients with YCMs. ConclusionsYCMs screening is a key test in the diagnostic approach to male infertility. Obtaining an adequate result allows choosing suitable assisted reproduction techniques, preventing unnecessary treatments and the transmission of genetic defects to offspring.

O-207 Incidence of Y chromosome microdeletions and microdissection testicular sperm extraction (micro TESE) in patients with Japanese azoospermic patients

Abstract Study question What is the frequency of azoospermia factor (AZF) microdeletions and sperm retrieval rate (SRR) by micro TESE in patients with these deletions? Summary answer AZFc is most frequent of Y chromosome microdeletions and a predictor of micro TESE outcome in Japanese azoospermic men. What is known already After Klinefelter syndrome, Y chromosome microdeletions are the second most frequent genetic cause of male infertility, with a prevalence of 2%-10% in non-obstructive azoospermia (NOA) and three spermatogenesis loci in the Y chromosome long arm (Yq11) have been classified as AZFa, AZFb, and AZFc. The classical correlation of histopathology phenotypes with these three microdeletions comprises of complete absence of germ cells (Sertoli cell-only syndrome) in patients with AZFa microdeletions, maturation arrest of meiosis in patients with AZFb microdeletions, and hypospermatogenesis in patients with AZFc microdeletions, however, individual variation in the extent of deletions has led to various spermatogenic phenotypes. Study design, size, duration We performed a retrospective study based on two reproduction centers in Japan and evaluated 1373 azoospermic patients in our clinics between September 2013 and December 2021. We investigated the frequency of AZF microdeletions and SRR by micro TESE in patients with these microdeletions and therefore aimed to evaluate the correlation between AZF microdeletions and micro TESE results. Participants/materials, setting, methods A total of 1373 azoospermic were enrolled. After the diagnosis of azoospermia, karyotype analysis and detection of Y chromosome microdeletions were performed on peripheral blood lymphocytes of these patients. Y chromosome microdeletions in AZFa, AZFb, and AZFc regions were detected using Promega Y Chromosome AZF Analysis System version 2.0 (Promega Co.). Twenty sequence-tagged sites within the AZF region of Yq11 and the sex-determining region Y gene were targeted for polymerase chain reaction (PCR) amplification. Main results and the role of chance One hundred and fifty-two AZF microdeletions (11.1%) were detected in the azoospermic patients. The most common deleted region was AZFc (60 cases, 4.4%). Among the patients, 17 (1.2%), 1 (0.1%), 42 (3.1%), 13 (1.0%), and 6 (0.5%) had AZFa, AZFa+b, AZFb+c, AZFb, and AZFa+b+c microdeletions, respectively. When the cases were grouped according to causes of infertility that could be detected, no Y chromosome microdeletions were detected in some groups (cases with Klinefelter Syndrome, hypogonadotropic hypogonadism, congenital absence of vas deferens, and 47, XYY karyotype). Fifty-three azoospermic men with AZFc microdeletions underwent micro TESE, and spermatozoa were detected in 88.7% (47/53) of these men. In contrast, we detected spermatozoa in only 20.4% (109/534) of the azoospermic men without AZF microdeletions. The SRR was much higher in patients with AZFc microdeletions than that of patients without AZF deletions. Although three azoospermic men with AZFb+c microdeletions had also undergone micro TESE following patient request, we did not retrieve spermatozoa. Limitations, reasons for caution We excluded post chemotherapy NOA showing 46, XX and AZFa+b+c deletions post bone marrow transplantation from female donor. Additionally, we did not detect AZFc partial deletion including gr/gr deletion. The cohort size of this study is not small, however, our screened population of infertile men may be biased. Wider implications of the findings NOA patients with AZFc microdeletions had a high percentage of successful sperm retrieval by micro TESE. Our study emphasizes that diagnosis of Y chromosome microdeletions is critical for preconception genetic counseling and provides clinically valuable prognostic information to couples considering surgical sperm retrieval. Trial registration number None

The genetic causes of male infertility: a Middle East and North Africa perspective.

Male infertility is attributable to 60% of total infertility cases and about 30-50% of these cases remain idiopathic. In the Middle East and North Africa region (MENA), male infertility affects about 22.6% of men of reproductive age. Male infertility is caused by a variety of factors, including endocrine disruption, exposure to toxins, lifestyle, genetic and epigenetic modifications. Genetic modifications, including chromosomal abnormalities, chromosomal rearrangements, Y chromosome microdeletions and single-gene mutations, explain for about 10-15% of infertility cases. Since genetic aberration is a key player in the pathogenesis of male infertility, it is important to explore the impact in the MENA region due to the high incidence of male infertility. Therefore, the current study aims to systematically analyse the literature regarding the impact and common causes of male infertility in the MENA region. To achieve this aim, a comprehensive literature search was performed on PubMed, Google Scholar, and Science Direct databases. Following the search, a total of 126 articles was retrieved, of which 12 were duplicates and another 69 articles did not meet the inclusion criteria, totaling the exclusion of 81 articles. Studies excluded were those that had patient populations originating outside the MENA region, review articles, non-English written articles, or studies where the patient population was under 18 years of age. Findings showed that the frequent genetic aberration leading to male infertility in these regions include Y chromosome microdeletions, gene polymorphisms or copy number variations, mitochondrial microdeletions and other genetic deletions or mutations. In lieu of this, diverse clinical genetic tests should be made available for the proper diagnosis of male infertility.

Prevalence of Y chromosome microdeletions among infertile Mongolian men.

ObjectiveY chromosome microdeletions are the second most common genetic cause of male infertility after Klinefelter syndrome. The aim of this study was to determine the patterns of Y chromosome microdeletions among infertile Mongolian men.MethodsA descriptive study was performed on 75 infertile men from February 2017 to December 2018. Y chromosome microdeletions were identified by polymerase chain reaction. Semen parameters, hormonal levels, and testis biopsy samples were examined.ResultsAmong 75 infertile men, two cases of Y chromosome microdeletions were identified. The first case had an AZFa complete deletion and the other had an AZFc partial deletion. This study found that the proportion of Y chromosome microdeletions among infertile Mongolian men was 2.66%.ConclusionThe findings can be applied to in vitro fertilization and assisted reproductive technology, and our results will help clinicians improve treatment management for infertile Mongolian couples.

Biallelic CFAP61 variants cause male infertility in humans and mice with severe oligoasthenoteratozoospermia

BackgroundThe genetic causes for most male infertility due to severe oligoasthenoteratozoospermia (OAT) remain unclear.ObjectiveTo identify the genetic cause of male infertility characterised by OAT.MethodsVariant screening was performed by whole-exome sequencing...