Genetic risk factors in infertile men with severe oligozoospermia and azoospermia.

BACKGROUND: Male infertility due to severe oligozoospermia and azoospermia has been associated with a number of genetic risk factors. METHODS: In this study 150 men from couples requesting ICSI were investigated for genetic abnormalities, such as constitutive chromosome abnormalities, microdeletions of the Y chromosome (AZF region) and mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. RESULTS: Genetic analysis identified 16/150 (10.6%) abnormal karyotypes, 8/150 (5.3%) AZFc deletions and 14/150 (9.3%) CFTR gene mutations. An abnormal karyotype was found both in men with oligozoospermia and azoospermia: 9 men had a sex-chromosomal aneuploidy, 6 translocations were identified and one marker chromosome was found. Y chromosomal microdeletions were mainly associated with male infertility, due to testicular insufficiency. All deletions identified comprised the AZFc region, containing the Deleted in Azoospermia (DAZ) gene. CFTR gene mutations were commonly seen in men with congenital absence of the vas deferens, but also in 16% of men with azoospermia without any apparent abnormality of the vas deferens. CONCLUSIONS: A genetic abnormality was identified in 36/150 (24%) men with extreme oligozoospermia and azoospermia. Application of ICSI in these couples can result in offspring with an enhanced risk of unbalanced chromosome complement, male infertility due to the transmission of a Y-chromosomal microdeletion, and cystic fibrosis if both partners are CFTR gene mutation carriers. Genetic testing and counselling is clearly indicated for these couples before ICSI is considered.     

Genetics: Mitotic chromosomal anomalies among 1210 infertile men

Detailed medical and clinical examinations were carried outon 1608 men attending an infertility clinic to determine ifany of those exhibiting abnormal semenograms also had any otherreadily identifiable clinical condition. In all, 1210 men showedabnormal semenograms according to World Health Organizationcriteria. Karyotyping of the white blood cells in these 1210men revealed 44 (3.6%) individuals with either autosomal orsex chromosomal aberrations. However, no single characteristicfeature of their semeno-gram or clinical condition was of anydiagnostic value to predict the existence of a chromosomal anomaly.     

Ultrasonic texture and volume of testicles in infertile men

Ultrasound scanning of the testes and surgical biopsy were performedin 95 infertile men to evaluate the use of ultrasound In maleinfertility. Ultrasonic testicular volume was calculated usingthree measurements and the formula of an ellipsoid, and theultrasonic texture was evaluated and given a score from 1 to5, indicating increasing degrees of irregularity. The medianscore was 3 (range 1–5), which was higher than previouslyfound in nonnal men (median score 2; range 1–5; P <0.0001). The ultrasonic texture score was lower in testes witha uniform pattern of 100% spermatogenic tubules compared withthe rest, both for the right (P < 0.001) and for the left(P < 0.0005) testis. Texture score was correlated with thenumber of obliterated tubules for both testes (P <0.001).The mean ultrasonic testicular volume of the right testis was10.30 ml, and that of the left 10.26 ml. Both were smaller comparedwith the findings in normal men (P <0.0001). Ultrasonic testicularvolume was negatively correlated with texture score (P <0.001). A positive correlation between ultrasonic volume andsperm count was seen (P < 0.001). Sperm count was negativelycorrelated with texture score if calculated together with datafrom 119 men from the general population (P < 0.001). Thestudy shows that ultrasonic volume and texture are valuableparameters in the evaluation of infertile men.     

200例男性不育患者的Y染色体微缺失检测

目的探讨男性不育患者与Y染色体微缺失之间的关系。方法利用15个Y染色体特异序列标签位点,以多重PCR法检测男性不育患者的Y染色体微缺失情况。结果 200例男性不育患者中共检出Y染色体微缺失7例,缺失率为3.5%。其中单纯A;ZFc缺失2例,缺失率为1%(2/200);A;ZFb缺失率为3例,缺失率为1.5%(3/200);单纯A;ZFa缺失2例,缺失率为1%(2/200),尚未发现联合缺失或大片段缺失患者。精液正常者(对照组)30例未发现Y染色体微缺失。结论 Y染色体微缺失是造成男性不育的常见病因之一。     

Chromosomal constitution of infertile men

Mitotic chromosome analyses performed on 820 infertile men revealed 60 (7.3%) men with some kind of chromosomal abnormality. Sex chromosomal abnormalities were detected in 28 (3.4%) and autosomal translocations in 9 (1.0%). Pericentric inversions of chromosome 9, with possible adverse effect on reproduction, was found in 23 (2.8%). Chromosome variants comprised a group of 77 (9.3%) subjects. We suggest that men with severe oligozoospermia and azoospermia should be considered for cytogenetical evaluation.     

Y chromosome microdeletion screening in infertile men in France: a survey of French practice based on 88 IVF centres

Y chromosome microdeletion screening is advised in cases of severely impaired spermatogenesis. Improvements in molecular biological techniques have made diagnosis more accessible in routine analysis. However, Y chromosome microdeletions are not diagnosed in all IVF centres. The aim of the present study was to determine the regulatory (indications, financing) and performance (methods, invoicing) conditions required for this analysis, in France. Microdeletion detection was found to be spreading fast and consistantly. It therefore seems necessary for a consensus to be reached on indications, with a view to a standardized technique, with a common effort of experts in the field. Financial management by the French Health Insurance bodies (Sécurité Sociale) would be an essential step towards routine adoption. Lastly, the answers to our questionnaire revealed a strong demand for information concerning this analysis.     

Manifestation of Y-chromosomal deletions in the human testis: a morphometrical and immunohistochemical evaluation

BACKGROUND: Deletions of the AZF (azoospermia factor) subregions on the Y chromosome are accompanied by a diverse spectrum of spermatogenic disturbances ranging from hypospermatogenesis to total depletion of germ cells causing infertility. The AZF region encodes gene products which are candidates for the genetic control of spermatogenesis. Although it is known which genes are involved, a general principle of cause and effect cannot yet be deciphered and the deletion type has non-uniform histological phenotypes. METHODS AND RESULTS: We analysed morphological parameters of testicular biopsies from 17 patients diagnosed for Y chromosome microdeletions. As control groups we analysed testes from patients with idiopathic Sertoli cell-only (SCO) syndrome (n = 11), mixed atrophy (n = 10) and complete spermatogenesis (n = 11). A detailed genetic analysis on the extension of the observed microdeletions revealed similar breakpoints in the distal and proximal region of the AZFc region, indicating a common mechanism of homologous recombination for such deletions, as has been suggested before. Morphometric parameters such as the diameter of the tubules, lumen, thickness of the lamina propria and height of the tubule epithelia were investigated. The diameter of the tubules from patients with microdeletions was found to be significantly smaller compared with patients with mixed atrophy. Considering also the size of the tubules, lumen and epithelia, a Y-chromosomal microdeletion represents an intermediate state between an idiopathic SCO and normal spermatogenesis. The immunohistochemical analysis of six different Sertoli cell markers, cytokeratin 18, vimentin, inhibin alpha subunit, 14-3-3 theta, FSH receptor and androgen receptor, revealed no impact of AZF deletion on the specific expression pattern of these genes. CONCLUSIONS: Our results suggest that, notwithstanding the deletion of a common region in the AZFc region, microdeletions of the Y chromosome lead to an intermediate status between idiopathic SCO and complete spermatogenesis, resulting in a heterogeneous histological profile regardless of the seminiferous activity. The Sertoli cell function seems not to be altered.     

Genotyping of Israeli infertile men with idiopathic oligozoospermia

Microdeletions of the long arm of the Y chromosome involving the azoospermia factor (AZF) region are associated with severe oligo- or azoospermia. Abnormal androgen receptor (AR) structure or function has also been implicated in male infertility. To assess the contribution of these genetic defects to male infertility, 61 Israeli men with severe oligo- (n = 15) or azoospermia (n = 46), were screened for Y chromosome microdeletions, and the AR-(CAG)n repeat length. Fifty fertile Israeli men were similarly analyzed. PCR amplification of 20-54 simple tag sequences (STSs) located at Yq was used to determine the rate and extent of Y chromosome microdeletions. PCR with primers flanking the AR-(CAG)n region and subsequent size fractionation on gradient acrylamide gels were used to determine AR-(CAG)n length. Five azoospermic individuals (5/61-8.2% and 5/46-10.8% of azoospermic patients) displayed Y chromosome microdeletions. The mean CAG repeat number in infertile men was 18.6 +/- 3.0 compared with 16.6 + 2.7 in fertile men (n = 50), a statistically significant difference (p = 0.003). Y chromosome microdeletions contribute to male infertility in our azoospermic population, and the mean length of the AR-CAG is significantly longer in our infertile population than in fertile men.     

Andrology: Clinical and biological characteristics of infertile men with a history of cryptorchidism

Out of 85 fertile and 1014 infertile men, two (2.4%) and 95(9.4%) respectively had a history of cryptorchidism. Thus cryptorchidismappears to be a risk factor for fertility since this differencewas significant. Further comparisons showed that the volumeof a former cryptorchid testis was smaller than the contralateralnormally descended one and that sperm output/concentration wasmore impaired in bilateral than in unilateral cryptorchidism.A retractile testis, defined as a testis reported by the patientto be spontaneously and regularly, i.e. at least once a week,ascending up into a supra-scrotal position, was more frequentin infertile men with a history of cryptorchidism than in fertilemen. Retractility was more frequent on the cryptorchid side,and was found more frequently after hormonal than after surgicaltreatment. Independently of all epidemiological and clinicalparameters studied, retractility was associated with a lowersperm output. Among the infertile men with a history of cryptorchidism,45% had an abnormally high scrotal temperature. This abnormaltemperature represented a pejorative risk factor for fertilityin this group, since it was associated with a more severelyimpaired spermatogenesis and a higher incidence of primary infertilitythan in infertile men with a history of cryptorchidism but normalscrotal temperatures.     

Elevation of serum testosterone and free testosterone after embolization of the internal spermatic vein for the treatment of varicocele in infertile men

BACKGROUND: To evaluate the effect of internal spermatic vein (ISV) embolization on levels of serum testosterone and free testosterone and on spermatogenesis. METHODS: The files of 83 infertile men treated for varicocele were reviewed for changes in serum testosterone, free testosterone and spermatogenesis after ISV embolization. RESULTS: Mean serum testosterone concentration rose after embolization by 43%, from 12.07 +/- 6.07 nmol/l to 17.22 +/- 8.43 nmol/l (P<0.001). Mean serum free testosterone concentration rose by 72%, from 5.93 +/- 2.44 nmol/l to 10.21 +/- 7.69 nmol/l (P<0.001). Mean sperm concentration increased from 7.49 +/- 1.73 x 10(6)/ml to 18.14 +/- 2.36 x 10(6)/ml (P<0.001); mean sperm motility increased from 21.74 +/- 2.47 to 34.47 +/- 2.27% (P<0.001); and mean sperm morphology increased from 6.63 +/- 1.07 to 13.08 +/- 1.44% (P<0.001). CONCLUSIONS: ISV embolization apparently induces an increase in both serum testosterone and free testosterone concentrations and in sperm parameters in infertile patient with varicocele, regardless of the size of the varicocele.     

180例无精子症或严重少精子症不育男性的Y染色体微缺失检测

目的探讨不育男性无精子症或严重少精子症与Y染色体微缺失之间的关系.方法利用9个Y染色体特异序列标签位点,以多重PCR法检测无精子症或严重少精子症患者的Y染色体微缺失情况.结果 180例无精子症或严重少精子症患者中共检出Y染色体微缺失15例,缺失率为8.3%.精液正常者(对照组)20例未发现Y染色体微缺失.9例Y染色体微缺失的无精子症患者睾丸细胞学检查均未发现精子.结论 Y染色体微缺失是造成男性精子发生障碍的常见病因之一.     

Screening for Y chromosome microdeletions in 226 Slovenian subfertile men.

BACKGROUND: The objective of this study was to estimate the frequency of Y chromosome microdeletions in the Slovenian population of infertile men and to analyse the consequences of mutation in respect to clinical severity and prognosis. METHODS: In a controlled clinical study at the university-based medical genetics service and infertility clinic, 226 infertile men undergoing ICSI were tested. The main outcome measures included polymerase chain reaction amplification of 16 genes and gene families and 42 sequence-tagged sites in the non-recombining region of the Y chromosome, semen, testicular volume and testicular histological analysis, serum FSH concentrations, fertilization and respective pregnancy rates. RESULTS: The incidence of deletions was 4.4%: 8.6% in men with azoospermia and 1.5% in men with oligoasthenoteratozoospermia. Isolated gene deletions were not identified. No statistically significant differences in clinical outcome measures were found in patients with mutations versus patients without mutations. High fertilization (49%) and pregnancy (43%) rates with sperm of patients with Y chromosome deletions were obtained. CONCLUSIONS: Testing for gene-specific microdeletions does not contribute significantly to the sensitivity of microdeletion test. Fertilization and pregnancy rates obtained using sperm of patients with Y chromosome deletions were comparable with those achieved in conventional IVF.     

Reproductive decisions of men with microdeletions of the Y chromosome: the role of genetic counselling.

Couples dealing with microdeletions of the Y chromosome have to make decisions about their reproductive future. Do they opt for intracytoplasmic sperm injection (ICSI), artificial insemination with donor insemination (AID) or no treatment? We analysed this decision in 28 couples and investigated the role of the counsellor and the counselling process on the final decision of the couple. Ten counsellors from six fertility clinics in The Netherlands and Belgium were interviewed about their genetic counselling of couples dealing with microdeletions. The answers to the questionnaire were converted to 11 dichotomous variables. Of the 1627 tested men in the six centres, 37 (2.3%) had a microdeletion in the AZFc region, a subregion of the AZF region on the Y chromosome important for normal spermatogenesis. The decisions of 28 of them could be analysed. Most couples chose ICSI (79%). The remaining couples chose donor insemination (7%) or refrained from treatment (14%). Several variables, including the counselling procedure, the counsellor and the available treatments in the fertility centre, influenced the decision of the couple. In conclusion, most couples dealing with microdeletions in the AZF region choose ICSI. Several aspects of the process of genetic counselling appear to be related to the final decision.     

618例不育男性的AZF基因微缺失分析

目的研究Y染色体AZF基因微缺失与男性不育的关系。方法应用多重PCR对618例男性不育患者进行Y染色体AZF基因的15个位点进行检测。结果一共检出Y染色体微缺失患者23例,占受检人群的3．72％,其中包括16例AZFc全部缺失、3例为AZFb＋c部分／全部缺失、3例为AZFa部分缺失和1例AZFa、AZFb、AZFc和AZFd四个区15个检测位点全部缺失。AZFc全部缺失患者中,中度至重度少精症13例,无精症3例;AZFb部分／全部缺失患者中,严重少弱精1例,无精症2例;AZFa部分缺失患者和15个位点全部缺失患者均为无精症。结论Y染色体AZF基因微缺失是男性不育的重要原因之一,该检测可为患者的诊断、治疗及遗传咨询提供依据。     

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.     

Seminal transforming growth factor-beta in normal and infertile men.

Transforming growth factor-beta (TGFbeta) is a cytokine with autocrine and paracrine action in the testis and potent immunoregulatory and anti-inflammatory activities. In the present study, we examined the concentration of latent (acid-activatable) and free (active) TGFbeta in seminal plasma from normal subjects (n = 23) and infertile (n = 40) patients, by using a TGFbeta specific immunoenzymological assay, and a bioassay (CCL64 cell line growth inhibition) detecting any form of TGFbeta. Free TGFbeta1 was present in normal subjects at a concentration (1.82 +/- 1.06 ng/ml) close to that known to give maximal stimulation in vitro. In pathological groups, the mean concentrations were not significantly different from the normal ones. Latent TGFbeta1 was present in normal seminal plasma at a high concentration (92.4 +/- 29.2 ng/ml). In subjects with pathologies of both testis and genital apparatus, or with epididymal occlusion, mean latent TGFbeta1 concentrations were normal, whereas transferrin concentrations were lower. The concentrations found in the epididymal occlusion group indicate that TGFbeta1 is, for a large part, secreted by the genital tract. In the testicular pathology group, TGFbeta1 concentrations were 130.7 +/- 61.2 ng/ml, a mean not statistically different from normal, although higher. No differences were found between patients with high and normal blood plasma follicle stimulating hormone, and this is consistent with the notion that most TGFbeta1 in seminal plasma is not of testicular origin. The TGFbeta bioassay ensured that immunologically detected TGFbeta was present in a bioactive or bioactivatable form. Furthermore, the values found in normal and pathological seminal plasmas were usually higher than those detected by the immunoassay, suggesting that other forms of TGFbeta might be present. Together, the present data show that very large amounts of TGFbeta are present in human seminal plasma. The TGFbeta ligand assay in the seminal plasma appears to indicate no differences between normal and infertile subjects.     

Sperm chromosome studies in an infertile man with partial, complete asynapsis of meiotic bivalents

Meiotic and sperm chromosome studies were carried out in two semen samples from an infertile man with a 46,XY karyotype, oligoasthenoteratozoospermia and abundant exfoliation of spermatogenic cells. Meiotic preparations showed partial, complete asynapsis in a large proportion of metaphase I figures observed, and absence of metaphase II figures, while 24 of the 30 sperm chromosome karyotypes analysed were normal. The remaining sperm karyotypes were as follows: one with structural abnormalities, one with both structural abnormalities and hypohaploidy and four with hypohaploidy. The total frequency of chromosomal abnormalities (6.7%) is similar to that obtained by us in normal men (10.9%). The frequency of spermatozoa with structural abnormalities (6.7%) was not significantly different from that obtained by us in normal men (6.9%). These results suggest that, in some cases, asynaptic spermatogenic cells do not proceed further than metaphase I and only normal germ cells continue spermatogenesis.     

Restoration of fertility in infertile mice by transplantation of cryopreserved male germline stem cells

BACKGROUND: The development of a spermatogonial transplantation technique has provided new possibilities for the treatment of male infertility. Previous studies have shown that spermatogonial stem cells could reinitiate spermatogenesis after cryopreservation and reintroduction into the seminiferous tubules of infertile recipient males, and this raised the possibility of banking frozen stem cells for male infertility treatment. It remains unknown, however, whether germ cells from freeze-thawed stem cells are fertile, leaving the possibility that the procedure compromises the integrity of the stem cells. METHODS AND RESULTS: Dissociated mouse testis cells were cryopreserved and transplanted into infertile recipient testes. The freeze-thawed testis cell populations contained higher concentrations of stem cells than fresh testis cell populations. Offspring were obtained from freeze-thawed stem cells transplanted into infertile males, and fertility restoration was more efficient in immature (5-10 days old) than in mature (6-12 weeks old) recipients. However, offspring were also obtained from infertile adult recipients using in-vitro microinsemination. CONCLUSIONS: This first successful application of frozen stem cell technology in the production of offspring by spermatogonial transplantation suggests the superiority of immature recipients for clinical applications. Thus, the combination of cryopreservation and transplantation of stem cells is a promising approach to overcome male infertility.