Normal Fertile Males Research Articles

High levels of bisphenol A among infertile men can impair spermatogenesis by oxidative stress and elevated levels of microRNA-337

BackgroundStudies have shown that Bisphenol A may interfere with the process of spermatogenesis and result in a decrease in the quality of semen. Nevertheless, the fundamental processes remain unclear. This study was done to investigate the connections between exposure to Bisphenol A, spermatogenesis with microRNA-337, and malondialdehyde in infertile men.MethodsThis study was a case–control study on 73 participants. Infertile group (1a): azoospermia (n = 16), infertile group (1b): oligozoospermia (n = 22), and control group (2): normospermic (n = 35) were enrolled in this study. Full history, local examination, semen analysis, and urine and blood samples were taken from all participants. Urinary Bisphenol A, malondialdehyde, and serum microRNA-337 were measured.ResultsThe mean Bisphenol A level in azoospermia group shows statistically significant increase comparing to fertile control group. The mean microRNA-337 level in oligozoospermia and azoospermia group shows statistically significant increase comparing to fertile controls. The mean malondialdehyde level in infertility groups shows statistically significant increase comparing to fertile control group. No linear correlations were recorded between Bisphenol A levels with semen quality parameters, hormonal profile, and microRNA-337.ConclusionWhile there is no significant change in the levels of Bisphenol A between normal fertile males and infertile males with oligozospermia, a significant elevation in the BPA level was observed in infertile males with azoospermia. A significant upregulation of the miRNA-337 gene expression in infertile males either oligozospermia or azoospermia was also observed. In addition, lipid peroxidation as evident by the significant elevation of MDA levels was marked among infertile patients.

Loss of SPACA1 function causes autosomal recessive globozoospermia by damaging the acrosome-acroplaxome complex.

Is the sperm acrosome membrane-associated protein 1 (SPACA1) gene critical to human globozoospermia? The biallelic loss-of-function (variant of SPACA1) causes globozoospermia as a result of acrosome-acroplaxome complex damage. SPACA1 expression decreases in patients with globozoospermia. Spaca1 gene-disrupted mice have abnormally shaped sperm heads that resemble those of human globozoospermia. We recruited a consanguineous family with two brothers affected by infertility as a consequence of globozoospermia. The semen analysis data and ART outcomes were collected. Exome sequencing (ES) was used to identify potential pathogenic variants. Protein-protein interaction (PPI) technologies and proteomic analysis were utilized to explore the pathogenic mechanism. Two globozoospermic brothers and their consanguineous parents were recruited to identify the potential pathogenic variant through ES. A homozygous nonsense variant in the SPACA1 gene in both brothers inherited from the heterozygous parents was identified. Twenty normal fertile males were recruited as controls. Sperm ultrastructure was observed with transmission electron microscopy. Western blotting was performed to measure SPACA1 expression level in the sperm from the patients. Mass spectrometry (MS) analyses were used to identify differentially expressed proteins and to investigate proteins that interact with SPACA1. Co-immunoprecipitation (co-IP), yeast two-hybrid (Y2H) and immunofluorescence colocalization assays were used to confirm the PPI. A nonsense variant (NM_030960.2: c.53G>A; p. Trp18*) in the SPACA1 gene was identified as the pathogenic variant in a family with globozoospermia. Patient IV:1 and Patient IV:2 had a phenotype very similar to that of Spaca1 gene-disrupted mice. The nonsense variant in SPACA1 led to premature transcriptional termination in the signal peptide, which was confirmed by western blotting. MS-based proteomics analysis showed that eight interactors of SPACA1 were differentially expressed in the patients' sperm, including actin-like Protein 7A (ACTL7A), an important component of the acrosome-acroplaxome complex. The PPI of SPACA1 and ACTL7A was confirmed via co-IP and Y2H assays. Immunofluorescence showed that SPACA1 and ACTL7A colocalized in mature sperm, revealing that these proteins were coexpressed spatially. Given the rarity of globozoospermia, only two patients from one family harbouring the SPACA1 variant were found. Future studies should evaluate SPACA1 variants in larger cohorts to corroborate this finding. This study revealed that the SPACA1 gene was critical for globozoospermia, which expanded the spectrum of causative genes for globozoospermia. This study also provided evidence for ICSI clinical outcomes for patients with SPACA1-deficient globozoospermia, which may guide clinical treatment strategies. Furthermore, this study explored the pathogenesis of globozoospermia caused by SPACA1 deficiency. This work was funded by the Precision Medical Research of National Key Research and Development Program (2018YFC1002400), National Natural Science Foundation of China (81873724), and Natural Science Foundation of Shanghai (20ZR1472700). The authors have no conflicts of interest to disclose. N/A.

Prevalence of Y chromosome microdeletion in azoospermic infertile males of Iraqi population

In human gamete development, the important period is spermatogenesis, which is organized by specific genes on Y chromosome. In some cases, the infertile men have shown microdeletions on Y chromosome, which seemed as if the structural chromosome variance is linked to the reduction of sperm count. This study aimed to determine the frequency and patterns of Y chromosome microdeletions in azoospermia factor (AZF) of Iraqi infertile males. Here, 90 azoospermic infertile males as a study group and 95 normal fertile males as control group were investigated for the microdeletion of AZF loci using numerous sequence-tagged sites. Of these 90 infertile male patients, 43 (47.8%) demonstrated Y chromosome microdeletions, in which AZFb region was the most deleted section inazoospermia patients (33.3%) followed by deletions in the AZFc region (23%), while there were no microdeletion in the AZFa region. The largest microdeletion involved in both AZFb and AZFc was detected in six azoospermic patients (6.7%). The present study demonstrated a high frequency of Y chromosome microdeletions in the infertile Iraqi patients which is not reported previously. The high frequency of deletions may be due to the association of ethnic and genetic factors. PCR-based Y chromosome screening for microdeletions has a potential to be used in infertility clinics for genetic counselling and assisted reproduction.

Serological Evaluation Of The Presence Of Anti-Spermatozoa Antibody In Infertile Males In Thi-QarGovernorate

A case control study was conducted in Thi-Qar governorate, south of Iraq, included a total 154 individuals 104 of theme were infertile patients while the other 50 males were fertile healthy control males, who attended the infertility center in AAl- Hussein Teaching hospital, from 20/10/ 2016 to 16/1/ 2018. aged between (l8-5l) years with mean of age was (29.95±0.68) and (50) healthy controls males aged between (23-37) years with mean age was (27.58±0.51). All patient submitted full reports about their medical status history, in addition to their infertility type (primary or secondary). Seminal fluid samples were collected by masturbation after three days of sexual avoidance. All patients and healthy control males were tested for presence of anti-spermatozoa antibodies in their seminal fluid. seminal fluid analysis in this study showed there were significant differences (p < 0.05) between fertile control group and infertile males (patients) in (The seminal fluid viscosity, Liquefaction time, Semen volume, Sperm motility and total sperm account while the results revealed there were no significant differences in the seminal fluid parameters between infertile patients and fertile control group in semen color, pH and sperm morphology. The overall prevalence of ASA in seminal plasma among studied papulation was 16.23% (25/l54). Among healthy control group anti-sperm antibody in seminal plasma were positive in 6% (3 /50) and negative in 94% (47/50) with mean concentration of anti-sperm antibody was 24.97±3.7 U/ml (normal range 0 – 60 U/ml). Among infertile patients anti-sperm antibody was positive in 21.15% (22/104) whereas negative in 78.84 % (82/104). The mean concentration of anti-sperm antibody was 40.71±2.32 U/ml. The statistical analysis revealed highly significant differences (P <0.05) in presence of ASA in seminal plasma of infertile patients compered to normal fertile males, also concentrations of ASA in seminal plasma was significantly higher in patients compered to healthy control males. In conclusion ASA was proportionally high among patient with infertility compered to healthy fertile control group.

Intra-individual Genomic Variation Analysis in Tissues (Blood vs. Testis) Through SNP Microarray: A Case Report of Two Patients with Idiopathic Sertoli Cell Only Syndrome (SCOS)

Background:Sertoli cell only syndrome (SCOS) or germ cell aplasia is characterized by the existence of only sertoli cells in the seminiferous tubule without any germ cells. SCOS is a multifactorial disorder but genetic factors play a major role in pathogenesis of idiopathic SCOS.Case Presentation:Two cases of idiopathic SCOS had been reported with no non-genetic factor in their medical history that could play a role in aetiology of SCOS. Also, two normal fertile males were recruited as controls in this study. For evaluation of genomic imbalance, karyotyping (G-banding), FISH, STS-PCR and SNP microarray were carried out. SNP microarray was carried out in DNA of peripheral blood for cases as well as controls. However, for cases, SNP microarray was conducted in DNA of testicular Fine needle aspiration cytology (FNAC).Conclusion:No chromosome abnormality and Yq microdeletion was found in cases as well as in controls. Microarray detected many CNVs and LOH that cover genes with spermatogenesis related function and PAR CNVs in both cases. Differential genomic variations were found in blood and testis for cases. Therefore, the evaluation of pathogenesis of idiopathic SCOS might be dependent on both tissue samples. The evaluation of genomic imbalances at both tissue levels should be done for a large cohort of patients.

The Role of Protamine 1 Gene Polymorphism and Anti FSH Antibody in Infertile Couples

Background: Infertility is a worldwide problem which affects approximately 15% of all couples, and is defined as, inability to conceive after twelve months of contraceptive-free unprotected intercourse. Materials and methods: Optical density of anti follicle stimulation hormone antibody in the serum was detected by enzyme–linked immunosorbent assay technique and from which anti follicle stimulation hormone antibody concentrations were evaluated according to cut-off. One polymorphic sites of Protamine 1 Gene was genotyped on 72 couples suffering from infertility. Another group consist of 20 couples apparently healthy individuals. Genotypes were determined by the polymerase chain restriction fragment length polymorphism (PCR-RFLP) method. Results: Anti FSH antibody result demonstrated differences in antibody values between the patients and the control group with significant statistically, the frequency of the reported SNP was no significantly different compared to normal fertile males, which suggest that such SNP may not serve as a good molecular marker for genetic diagnosis of male infertility. Conclusion: The SNP G197T are completely absent and are not associated with male infertility with aforementioned, therefore these SNPs may not represent as a molecular marker for the diagnosis of genetic cause of male infertility in our studied population.

TTY2 genes deletions as genetic risk factor of male infertility.

Y chromosome has a number of genes that are expressed in testis and have a role in spermatogenesis. TTY2L12A and TTY2L2A are the members of testis transcript Y2 (TTY2) that are Y linked multi-copy gene families, located on Yp11 and Yq11 loci respectively. The aim of this study was to investigate frequency of TTY2L12A and TTY2L2A deletions in azoospermic patients compared with fertile males. This study was performed on 45 infertile males with idiopathic azoospermia without any AZF micro deletions (group A), 33 infertile males with azoospermia which do not screened for AZF micro deletions (group B) and 65 fertile males (group C), from October 2013 to April 2015 in west of Iran. Polymerase chain reaction (PCR) method was used for detection of TTY2L12A and TTY2L2A gene deletions in studied groups. No deletions were detected in normal fertile males of group C. 1 out of 45 azoospermic males of group A (2.22%) and 3 out of 33 azoospermic males of group B (9.09%) had TTY2L2A deletion (p= 0.409 and p= 0.036 respectively), also 1 out of 45 azoospermic males of group A (2.22%) and 4 out of 33 azoospermic males of group B (12.12%) had TTY2L12A deletion (p= 0.409 and p= 0.011 respectively). None of azoospermic males in Group A and B had deletions in both genes. Our data showed significant correlation between non-obstructive azoospermia and TTY2L12A and TTY2L2A deletions. Thus, it seems that TTY2L12A and TTY2L2A deletions can consider as one of the genetic risk factors for non-obstructive azoospermia.

Evaluation of a Sterile‐Male Release Technique: A Case Study of Invasive Sea Lamprey Control in a Tributary of the Laurentian Great Lakes

AbstractInvasive species can have detrimental impacts on native species and ecosystem services for humans. A technique that involves sterilization and release of males into wild populations of the same species can be useful in the control of invasive or pest species. A sterile‐male release technique (SMRT) was used on a novel vertebrate system, the invasive Sea Lamprey Petromyzon marinus in the Great Lakes, in an attempt to control population size. Sea Lamprey populations in the Great Lakes have been suppressed since the 1950s by (1) pesticide applications to kill larvae in streams and (2) barriers to block upstream spawning migrations. Here, we present a literature review and meta‐analysis of the SMRT by using a case study from the St. Marys River, where the SMRT was applied as an experimental method of Sea Lamprey control from 1991 to 2011. Observations obtained from the St. Marys River during and after SMRT application were used to evaluate whether the SMRT was effective at suppressing reproduction. Males were successfully sterilized and exhibited normal mating behaviors. The survival of embryos in nests was lower during the years when the SMRT was applied (32%) than during the post‐SMRT period (67%). The overall distribution of embryo viability in the river shifted after the SMRT was applied. During the SMRT application period, the observed ratios of sterile males to normal (fertile) males on nests were significantly different than expected, possibly due to an underestimation of adult Sea Lamprey abundance in the St. Marys River. Even at lower sterile male : normal male ratios, the number of viable embryos produced would have declined, but the level of reproductive suppression required to overcome recruitment variability was unclear. We discuss the effectiveness of the SMRT as it pertains to the Sea Lamprey, and we highlight difficulties in data interpretation and provide future direction for similar control programs.Received December 1, 2015; accepted June 16, 2016 Published online August 31, 2016

H19 gene methylation status is associated with male infertility

The present study investigated the H19 gene methylation status in male infertility. Between March 2013 and June 2014, semen samples were collected from 15 normal fertile males and 15 males experiencing infertility, and routine analysis and sperm morphological assessment were performed. The semen samples were subjected to density gradient centrifugation to separate the sperm fraction, and genomic DNA from the sperms was extracted and treated for bisulfite modification. Following in vitro amplification by polymerase chain reaction (PCR), the purified PCR products were cloned into pMD®18-T vectors and successful cloning was confirmed by restriction enzyme digestion. Positive clones were sequenced and the DNA methylation status was analyzed. The overall methylation rate in the normal fertile group was 100% (270/270), whereas in the infertile group the methylation rate was lower at 94.1% (525/558), revealing a statistically significant decrease in overall methylation rate in the infertile patients compared with the control group (χ2=15.12; P<0.001). The average methylation rates of CpG 1, 3 and 6 in the infertile group were statistically different from those in the normal control group (all P<0.05). The abnormal methylation of imprinted gene H19 is associated with male infertility, suggesting that H19 may serve as a biomarker for the detection of defects in human spermiogenesis.

Copy number variation and microdeletions of the Y chromosome linked genes and loci across different categories of Indian infertile males.

We analyzed 34 azoospermic (AZ), 43 oligospermic (OS), and 40 infertile males with normal spermiogram (INS) together with 55 normal fertile males (NFM) from the Indian population. AZ showed more microdeletions in the AZFa and AZFb regions whereas oligospermic ones showed more microdeletions in the AZFc region. Frequency of the AZF partial deletions was higher in males with spermatogenic impairments than in INS. Significantly, SRY, DAZ and BPY2 genes showed copy number variation across different categories of the patients and much reduced copies of the DYZ1 repeat arrays compared to that in normal fertile males. Likewise, INS showed microdeletions, sequence and copy number variation of several Y linked genes and loci. In the context of infertility, STS deletions and copy number variations both were statistically significant (p = 0.001). Thus, semen samples used during in vitro fertilization (IVF) and assisted reproductive technology (ART) must be assessed for the microdeletions of AZFa, b and c regions in addition to the affected genes reported herein. Present study is envisaged to be useful for DNA based diagnosis of different categories of the infertile males lending support to genetic counseling to the couples aspiring to avail assisted reproductive technologies.

Organizational and Functional Status of the Y-linked Genes and Loci in the Infertile Patients Having Normal Spermiogram

Male fertility is an orchestrated interplay of loci on the Y chromosome with a number of genes from across the other chromosomes. In this context, micro-deletions in the Y chromosome have been correlated with spermatogenic failure often leading to infertility. However, causes of infertility in the patients with the normal spermiogram have remained unclear and therefore pose another level of challenge. In the present study, we analyzed 64 STSs, studied different Y-linked genes and loci and conducted single nucleotide variant (SNV) analyses in 31 infertile males with normal spermiogram along with 67 normal fertile males (NFMs) to gain an insight into the organization of their Y chromosome. Further, employing quantitative real-time PCR (qPCR), we studied copy number variation of DYZ1 arrays and three genes and mutational status of SRY by direct sequence analyses. STS analyses of the AZFa, b and c regions in these patients showed known and new mutations. Further, copies of DAZ and BPY2 in the patients were found to be affected compared to those in NFMs. All the patients had normal copy number of the SRY however its sequence analysis (in silico) showed mutations in eight patients. In four of these eight patients, SRY mutations resulted into truncated proteins. Similarly, DYZ1 analysis showed micro-deletions and it's much reduced copy number as compared to those in NFMs. Present study in males with unexplained infertility revealed deletions similar to those observed in oligospermic and azoospermic patients. Thus, there are some common but still unknown factors underlying infertility in these patients irrespective of their spermatogenic status. This work is envisaged to augment DNA diagnosis, proving beneficial in the context of in vitro fertilization (IVF) and genetic counselling.

Study of Serum Selenium Level And Its Effect on Male Infertility

Some of the biomedical research has shown interest in the anti-oxidant activity of selenium which could be due to evidences reported that oxidative damage to cells and cell membranes is one of the causative agents in the pathogenesis of many disease states including male infertility. The present study was undertaken with the objective to measure role of Selenium levels in male infertility and assess the effect on different parameters like sperm count, sperm morphology & sperm motility. Our study included 58 infertile and 52 normal fertile males in age group of 22-50 years. The apparent difference in serum Selenium between the normal fertile controls and infertile cases turned out to be statistically significant ( p <0.01) and there seems to be a positive correlation between low serum Selenium levels and semen quality parameters like count, motility and morphology. It is proposed that Selenium acts as free radical scavenger and improves semen quality by virtue of antioxidant component of selenoprotein and classical glutathione peroxidase (GPx) Key words : Infertility Selenium Glutathione peroxidase

Feasibility study on cytological sperm bundle assessment of F1 progeny of irradiated male painted apple moth (Teia anartoides Walker; Lepidoptera: Lymantriidae) for the sterile insect technique

The advantage of inherited sterility over complete sterility in lepidopteran sterile insect technique programs results from the improvement of mating fitness of male-only releases with wild females, and the resulting large multiplier effect from viable but sterile progeny from every mating. The deleterious effects induced by irradiation are inherited by the F1 generation, but it is very difficult to measure population introgression at that stage, and the alternative has been to await population suppression at the F2 generation. This work, conducted in support of the successful elimination of painted apple moth (Teia anartoides) in New Zealand, aimed to determine the feasibility of a cytological assessment on the F1 sperm bundles of this species, as a new forensic biosecurity tool providing information for decision support. The technique successfully distinguished the homogeneous nuclei clusters of eupyrene bundles of the normal fertile males from the heterogeneously stained nuclei clusters of the F1 progeny. However, the challenge for the technique involved obtaining good specimens for cytological diagnosis. The percentage of positive staining results was correlated strongly with survival, which was <5 days. Moths that had spent 24 h on a sticky base in a monitoring trap were equivalent to freshly killed specimens, but the efficacy of the technique decreased after that. Some specimens that were ‘dead’ to the naked eye but potentially alive internally produced reliable results. The technique may be potentially useful as a forensic biosecurity tool in the future when a communicating trap is deployed, ensuring that fresh specimens could be used to monitor the success of inherited sterility in population suppression or eradication.

Deoxyribonucleic acid (DNA) content of morphologically different sperm types from normal and subfertile human males.

20 male patients (G2), affected by idiopathic oligozoospermia, and 10 normal fertile males (G1) were investigated. The DNA content of 50 Feulgen stained sperm heads per subject was determined, using single cell photometry. In a second step area, circumference, length, and width of the same heads were measured, using a semi-automatic image analysis system. Considering only morphologically normal heads, the mean DNA content is only slightly smaller in G2 than in G1. On the contrary, the DNA variation is strongly higher in G2 than in G1. Unfortunately, morphologically defect heads show an increased DNA variation, too. Thus, determining the DNA variation of a semen, containing many morphologically defect heads, a combined determination of the DNA content and head morphology is necessary. This can only be achieved by single cell cytophotometry, which is therefore superior to flow cytophotometry as regards this problem. Many heads with a strongly abnormal DNA content do not show any morphological abnormalities. These subcellular changes can only be detected by the determination of the DNA content.

Analysis of sex chromosome abnormalities using X and Y chromosome DNA tiling path arrays

Background: Array comparative genomic hybridisation is a powerful tool for the detection of copy number changes in the genome. Methods: A human X and Y chromosome tiling path array was...

AZFc somatic microdeletions and copy number polymorphism of the DAZ genes in human males exposed to natural background radiation

Ionizing radiations are known to induce tumors, chromosomal lesions and minisatellite length variations, yet no correlation has been demonstrated between radiation exposure and indels or copy number polymorphism (CNP) of the genes. We studied the impact of natural background radiation (NBR) on the human Y chromosome owing to its haploid status and clonal inheritance. We analyzed the AZFc region using the DNA from blood and semen of 100 males living near the coastal peninsula in Kerala (India), exposed to NBR along with other 50 normal fertile males. STS mapping of AZFc region showed random microdeletions without conclusive gr/gr or b1/b3 phenotypes. Using a highly specific novel Taqman assay based on sY587 sequence, we detected four copies of the DAZ genes in normal males and 4-16 in those exposed to NBR. Amongst NBR exposed males with multiples copies of the DAZ genes, 75% showed varying FISH signals for DAZ genes with cosmid 18E8 whereas 30% showed mosaicism in terms of presence/absence of the signals in 6-8% cells and unexpected number of signals in 9-12% interphase nuclei. Startlingly, all germline samples studied were found to be free from AZFc microdeletions and CNP of the DAZ genes. Since the DAZ genes are heavily implicated with the germ cell development, the cells with DAZ deletion/duplication are unlikely to survive. Alternatively, an innate mechanism may be operative to protect the germline from the effects of NBR.

Role of intratesticular ultrasonographic and Doppler flow analyses in evaluating gonadal status in male survivors of childhood malignancy

Fifty-seven males, previously treated for malignancies in childhood, and who refused to masturbate for semen analysis, were submitted to hormonal, ultrasonographic, and Doppler evaluation to assess the effects of chemotherapy/radiotherapy on gonadal function. Nineteen normal healthy fertile males served as controls. In the studied population, FSH was inversely correlated with testicular volume and directly correlated with testicular vascularization, suggesting that ultrasonographic and color Doppler scanning of the testes may be used, if a sperm count is not available, to indirectly assess the gonadal function.

Reduced oocyte activation and first cleavage rate after ICSI with spermatozoa from a sterile mouse chromosome mutant.

Male mice, heterozygous for two semi-identical reciprocal translocations T(1;13)70H and T(1;13)1Wa are usually sterile. We have investigated this oligoasthenoteratozoospermic mouse model using ICSI. B6D2F1 oocytes were injected with epididymal or testicular sperm from fertile or sterile translocation carriers and from chromosomally normal fertile controls. ICSI efficiency was determined by pronucleus formation and first cleavage rates. For arrested zygotes, cell cycle progression was evaluated by BrdU incorporation and incubation with okadaic acid. Epididymal sperm from infertile translocation carriers showed a slightly lower fertilization rate (70% vs. 92%, 95% and 95% for fertile translocation carriers and two groups of normal fertile control males, respectively) and a severely reduced cleavage rate (33% vs. 87%, 96% and 89% for the same control groups). However, the use of testicular sperm significantly improved the cleavage rate (62% vs. 83% for normal fertile controls). Development of arrested zygotes was delayed or blocked during S- and G2-phase. Whereas control testicular and epididymal sperm performed equally well, the use of testicular sperm from oligospermic T/T' males significantly increased first cleavage rates when compared to the low rates with epididymal sperm. Epididymal storage in oligospermics may negatively influence zygote division.

Cystic fibrosis transmembrane conductance regulator gene screening and clinical correlation in Taiwanese males with congenital bilateral absence of the vas deferens.

In Taiwan, an area with a very low incidence of cystic fibrosis (CF), we first screened for the most common mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene and looked for clinical correlations in 27 patients with clinically diagnosed congenital bilateral absence of the vas deferens (CBAVD). The clinical results showed that none of the 27 patients had CF symptoms. We did not detect any definite renal anomaly ultrasonographically. Mutation analysis was carried out on these 27 cases and 46 normal fertile males as controls. No mutations of Delta F508 or R117H were identified in any of the samples analysed. In the screening of IVS8-poly T, five of the 27 CBAVD patients showed the homozygous genotype for 5T/5T, 14 showed the heterozygous genotype for 5T/7T and eight showed the homozygous genotype for 7T/7T. The frequency of 5T alleles was 44.4%, which was significantly higher than in the 46 normal fertile males, for which there was a 5T frequency of 5.4%. The absence of major mutations of CFTR genes could be related to the much lower CF incidence in Taiwan. Further investigations into differences in the mutation spectrum of other CFTR genes are needed for a better understanding of the development of Taiwanese-Oriental CBAVD.

Genetic analysis of males from intracytoplasmic sperm injection couples.

A total of 392 men referred for intracytoplasmic sperm injection (ICSI) participated in genetic analysis. The control group consisted of 100 normal fertile males. Chromosome and DNA analyses were performed to investigate the frequency of Y-chromosome microdeletions and CFTR mutations (the controls underwent DNA analysis only). An abnormal karyotype was found in 4.6% of all males, but the frequency among men with azoospermia was higher, at 11.7%. Y-chromosome microdeletions were found only among men with azoospermia (6.5%) and men with extreme oligospermia (2%). Compound heterozygosity for CFTR mutations was found in men with azoospermia (3.9%) and congenital bilateral absence of vas deferens (CBAVD) only. We conclude that all couples referred for ICSI should be offered chromosome analysis. DNA analysis for Y-chromosome microdeletions should be reserved for men with azoospermia or extreme oligospermia (<1 x 106 spermatozoa). Analysis for CFTR mutations should be limited to those with obstructive azoospermia or those with a family history of cystic fibrosis.