Idiopathic cases of male infertility from a region in India show low incidence of Y-chromosome microdeletion

Prevalence of Y chromosome microdeletion in azoospermia factor subregions among infertile men from West Bengal, India

Background

Etiology of male infertility is intriguing and Y chromosome microdeletion within azoospermia factor (AZF) sub‐regions is considered major cause. We conducted a screening for Y chromosome microdeletion in an infertile male cohort from West Bengal, India to characterize Y chromosome microdeletion among infertile men.

Methods

We recruited case subjects that were categorized on the basis of sperm count as azoospermia (N = 63), severe oligozoospermia (N = 38), and oligozoospermia (N = 17) and compared them with age, demography, and ethnicity matched healthy proven fertile control males (N = 84). Sequence Tagged Site makers and polymerase chain reaction based profiling of Y chromosome was done for AZF region and SRY for cases and controls.

Results

We scored 16.1% of cases (19 out of 118) that bear one or more microdeletions in the studied loci and none among the controls. The aberrations were more frequent among azoospermic males (17 of 19) than in severe oligozoospermic subjects (2 of 19).

Conclusion

Our study provides the results of screening of the largest Bengali infertile men sample genotyped with the maximum number of STS markers spanning the entire length of Y chromosome long arm. Y chromosome microdeletion is a significant genetic etiology of infertility among Bengali men.

Epigenetics and genomics in Klinefelter syndrome

Since the first description of Klinefelter syndrome (KS) was published in 1942 in The Journal of Clinical Endocrinology, large inter-individual variability in the phenotypic presentation has been demonstrated. However, our understanding of the global impact of the additional X chromosome on the genome remains an enigma. Evidence from the existing literature of KS indicates that not just one single genetic mechanism can explain the phenotype and the variable expressivity, but several mechanisms may be at play concurrently. In this review, we describe different genetic mechanisms and recent advances in the understanding of the genome, epigenome, and transcriptome of KS and the link to the phenotype and clinical heterogeneity. Future studies are needed to unite clinical data, genomic data, and basic research attempting to understand the genetics behind KS. Unraveling the genetics of KS will be of clinical relevance as it may enable the use of polygenic risk scores to predict future disease susceptibility and enable clinical risk stratification of KS patients in the future.

Incidence of Y chromosome microdeletions in patients with Klinefelter syndrome

PURPOSE

The aim of this study was to study the incidence of Y chromosome microdeletions in a Caucasian population of Klinefelter syndrome (KS) patients and to investigate the possible association between Y chromosome microdeletions and KS.

MATERIALS AND METHODS

We conducted a retrospective study on 118 KS patients, 429 patients with non-obstructive azoospermia (NOA), and 155 normozoospermic men. Eight of the 118 KS patients had undergone testicular sperm extraction (TESE). All patients underwent semen examination and Y chromosome microdeletions evaluated by PCR, using specific sequence tagged site (STS) primer sets, which spanned the azoospermia factor AZFa, AZFb, and AZFc regions of the Y chromosome.

RESULTS

Semen analysis of the KS group revealed: 1 patient with oligozoospermia, 1 with severe oligoasthenoteratozoospermia, 2 with cryptozoospermia, and 114 with azoospermia. Eight of the 114 azoospermic KS patients underwent TESE, and spermatozoa were recovered from three of these, all of whom had non-mosaic karyotype 47, XXY. 10.7% of the NOA patients presented AZF microdeletions. In 429 cases with NOA, 8 cases had AZFa + b + c deletion, 6 cases had AZF b + c deletion, 4 cases had AZFa microdeletion, 8 cases had AZFb microdeletion, and 20 cases had AZFc microdeletion. Just one KS patient (0.8%) presented microdeletion in the AZFc region.

CONCLUSION

The percentage of microdeletions in KS patients was lower than in NOA patients, suggesting that AZF microdeletions and KS do not have a causal relationship and that Y chromosome microdeletions are not a genetic factor linked to KS.

A multi-faceted approach to understanding male infertility: gene mutations, molecular defects and assisted reproductive techniques (ART)

BACKGROUND

The assisted reproductive techniques aimed to assist infertile couples have their own offspring carry significant risks of passing on molecular defects to next generations.

RESULTS

Novel breakthroughs in gene and protein interactions have been achieved in the field of male infertility using genome-wide proteomics and transcriptomics technologies.

CONCLUSION

Male Infertility is a complex and multifactorial disorder.

SIGNIFICANCE

This review provides a comprehensive, up-to-date evaluation of the multifactorial factors involved in male infertility. These factors need to be first assessed and understood before we can successfully treat male infertility.

Identification of biochemical differences between different forms of male infertility by nuclear magnetic resonance (NMR) spectroscopy

PURPOSE

The aim of this study was to analyze the seminal plasma of patients with idiopathic/male factor infertility and healthy controls with proven fertility by NMR spectroscopy, with a hope of establishing difference in biomarker profiles, if any, between the groups.

METHODS

A total of 103 subjects visiting the infertility clinic of Manipal University with normozoospermic parameters, oligozoospermia, asthenozoospermia, azoospermia and teratozoospermia were included. Semen characteristics were analysed by standard criteria. Seminal plasma was subjected to NMR spectroscopy at a 700 MHz (1)H frequency. The resultant data was analyzed by appropriate software.

RESULTS

The analysis revealed significant differences between the fertile control group and other forms of male infertility. Interestingly, seminal plasma profile of the idiopathic infertility group showed distinct segregation from the control population as well as other infertile groups. The difference in biomarker profiles between the idiopathic infertility and the rest of the groups combined could originate from either the up-regulation or down regulation of a several compounds, including lysine, arginine, tyrosine, citrate, proline and fructose.

CONCLUSION

Our data suggests the presence of a metabolic reason behind the origin of idiopathic infertility. (1)H NMR based metabonomic profiling based on concentration of biomarker lysine has the potential to aid in the detection and diagnosis of idiopathic infertility in an efficient manner.

Genetic Risk of Azoospermia Factor (AZF) Microdeletions in Idiopathic Cases of Azoospermia and Oligozoospermia in Central Indian Population

BACKGROUND

Genetic factors cause about 15% of male infertility. Azoospermia factors (AZFa, AZFb, and AZFc) present on Yq are most important for spermatogenesis. We have made an attempt to evaluate the frequencies of microdeletions of AZFa, AZFb, AZFc in idiopathic cases of azoospermia and oligozoospermia from central Indian population.

MATERIALS AND METHODS

We have analyzed a total of 156 subjects (95 oligozoospermia and 61 azoospermia) & 50 control subjects. DNA samples were analyzed for microdeletions of Y chromosome by PCR-screening of 18 sequences-tagged-site (STS) markers from different region of the AZF on Yq and SRY on Yp.

RESULTS

Out of 156 cases analyzed, 13 (8.33%) subjects (8 azoospermia and 5 oligozoospermia) showed partial deletion of AZF regions, of which deletion in AZFc region was the most common (84.6%) followed by AZFb (15.4%) and AZFa (15.4%). The sites and sizes of deletions varied among patients. Histological study of the testicular tissue of the available subjects, who showed microdeletions of Y chromosome, showed spermatogenic arrest at different stages. The frequency of Y chromosome microdeletion in our subjects was 8.33%.

CONCLUSION

Some Indian studies reported low frequencies of microdeletions than that of our result. We suggest that the frequency of deletions may be affected by the involvement of different genetic factors, ethnic population and different geographical regions. PCR based Y chromosome screening for microdeletions will be useful and great help to infertility clinics for genetic counselling and assisted reproduction.

Y chromosome microdeletions in infertile men: prevalence, phenotypes and screening markers for the Indian population

PURPOSE

Yq microdeletions are the leading genetic cause of male infertility and its detection is clinically relevant for appropriate genetic counseling. We aimed to determine the prevalence and type of Yq microdeletions, the associated seminal phenotypes and the STS markers that are relevant for its testing in Indian population.

METHODS

Yq microdeletion analysis was carried out in 1,636 infertile cases in our centers. Additional data was collected from published studies in Indian population leading to a total of 3,647 cases.

RESULTS

In our cohort, 3.4 % (56/1,636) of infertile men had Yq microdeletions. Combining the data from other published studies identified 215/3,647 (5.8 %) infertile individuals to harbor Yq microdeletions; with 6.4 % in azoopsermia, 5.8 % in oligozoospermia and 3.2 % in oligoasthenozoospermia and teratozoospermia cases. No significant differences in the deletion frequencies were observed between idiopathic vs non idiopathic cases (5.8 vs 8.6 % respectively). Deletions of AZFc were at highest frequency (46.6 %) with double deletions most commonly observed in azoospermic subjects. With respect to the STS markers, screening with the six European Academy of Andrology (EAA) markers would miss 3.1 % of cases; additional non EAA markers that would contribute significantly to screening are sY746, sY82, sY121, sY128, sY130, sY143, sY145 & sY160.

INTERPRETATIONS AND CONCLUSIONS

The frequency of Yq microdeletions is lower in Indian population as compared to Western counterparts. There is no major association of Yq microdeletions with seminal parameters or cause of infertility. Clinically it will be necessary to offer Yq microdeletion testing to all the classes of infertile men. The EAA markers may not be adequate to detect microdeletions in Indian infertile men.

Mystery of idiopathic male infertility: is oxidative stress an actual risk?

OBJECTIVE

To study the role of oxidative stress in sperm dysfunction in Turkish idiopathic infertile men.

DESIGN

Prospective study.

SETTING

Medical laboratory.

PATIENT(S)

Semen samples from 28 idiopathic infertile men and 14 fertile men.

INTERVENTION(S)

Sperm DNA fragmentation and reactive oxygen species (ROS) formation were assayed with the terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL) test and 2',7'-dichlorodihydrofluorescein, respectively. Seminal plasma protein carbonyl groups (PC), nitrotyrosine (NT), malondialdehyde (MDA), and total thiol (SH) levels and ferric reducing antioxidant power (FRAP) were determined.

MAIN OUTCOME MEASURE(S)

Sperm DNA fragmentation in relation to ROS formation and seminal plasma oxidative parameters.

RESULT(S)

The number of TUNEL-positive spermatozoa from idiopathic infertile men was higher than from fertile men, and ROS formation was increased as well in infertile males. A positive correlation was detected between TUNEL-positive cells and ROS content. Seminal plasma MDA, PC, and NT levels were elevated in idiopathic infertile males. No difference was observed in the total SH content and FRAP. Seminal plasma MDA levels correlated positively with both NT and PC levels. Positive correlations were detected between DNA fragmentation and MDA, NT, and PC of seminal plasma, and between sperm ROS content and MDA levels.

CONCLUSION(S)

The results of this study support the presence of oxidative stress in sperm dysfunction in Turkish idiopathic infertile men.

Chromosomal defects in infertile men with poor semen quality

PURPOSE

To assess the incidence and the type of chromosomal aberrations in males with infertility we reviewed cytogenetic results in 76 Tunisian infertile men (54 nonobstructive azoospermia and 22 oligo-asthenospermia).

METHODS

Karyotyping was performed on peripheral blood lymphocytes according to the standard methods. Molecular diagnosis of classical and partial Y-chromosomal microdeletions was performed by amplifying Y-specific STSs markers.

RESULTS

Various numerical and structural chromosome abnormalities were identified in 15 patients (19.48%). The occurrence of chromosomal abnormality in the azoospermics and severe oligo-asthnospermic was 21.7% and 13.5%, respectively. The most common was Klinefelter syndrome, accounting for 10 of the 15 cytogenetic defects. The total frequency of Y chromosomal microdeletions was 17.1%, with respective frequencies in azoospermic and severe oligospermic groups, 11.1% and 31.8%. The most frequent of Y chromosomal deletions were the partial ones (11.1% in azoospermic and 27.2% in oligospermic).

CONCLUSION

The occurrence of chromosomal abnormalities among infertile males strongly suggests the need for routine genetic testing and counseling prior to the employment of assisted reproduction techniques.

Surgery for azoospermia in the Indian patient: Why is it different?

Obstructive azoospermia is one of the few surgically correctable causes of male infertility. The outcomes of surgery in these patients are variable and often dependent upon the diagnosis and surgical expertise. We aimed to review the reported outcomes in Indian patients and evaluate potential reasons why these outcomes may be different from those reported from other regions. A search was performed on Medline/Pubmed using relevant keywords to identify publications from India on surgical management of azoospermia. The same search was repeated on Google and on the website of the Indian Journal of Urology. Personal emails were sent to prominent urologists performing surgery for azoospermia in India to obtain their opinions and reprints of their published articles. These were then reviewed. Very few articles were identified that pertained to the original search. A large majority of patients are diagnosed with idiopathic infertility. The outcomes of surgery where a clear diagnosis can be made are generally good and often comparable with the published literature. Infections are probably an under-diagnosed etiology. More research and publications are required to determine the etiology of obstructive azoospermia in the Indian men. These would help appropriate patient counseling and treatment.

Use of ethnicity-specific sequence tag site markers for Y chromosome microdeletion studies

INTRODUCTION

Microdeletions in the azoospermia factor region on the long arm of Y chromosome are associated with spermatogenic failure. There are many markers for the diagnosis of Y chromosome microdeletion analysis, but in routine practice only a limited set of markers can be tested.

OBJECTIVE

The objectives of this study were to determine the frequency of Y chromosome microdeletion in idiopathic cases of male infertility in India, to attempt genotype-phenotype correlation, and to evaluate whether markers to be tested for diagnosis of Y chromosome microdeletion should be ethnicity specific.

METHODS

Microdeletions in the Y chromosome were analyzed in 200 infertile males. The six sequence tag site (STS) markers prescribed by the European Academy of Andrology (EAA) were used initially. Patients in whom no deletions were detected by use of these markers were tested by markers selected from other studies from India.

RESULTS

The STS markers prescribed by EAA detected deletions in only 6 (3%) of 200 infertile males. However, markers selected from previous Indian studies showed deletions in an additional 15 (7.5%) of infertile males. Overall, Y chromosome microdeletions were observed in 21 (10.5%) of 200 patients. Of these, 13 were cases of azoospermia and 8 were cases of severe oligospermia.

CONCLUSION

The markers prescribed by EAA alone are not suitable for the diagnosis of Y chromosome microdeletions in infertile males. The protocol for identification of Y chromosome microdeletions in cases of nonobstructive azoospermia/severe oligospermia would have to include a different set of STS markers.

The likelihood of finding mature sperm cells in men with AZFb or AZFb-c deletions: six new cases and a review of the literature (1994-2010)

OBJECTIVE

To reassess the predictive value of detecting sperm cells in men with AZFb or AZFb-c deletions.

DESIGN

Retrospective analysis of previously reported men with AZFb or AZFb-c deletions and the addition of six new cases.

SETTING

Fertility institution.

PATIENT(S)

Men with both sequence tagged site marker identification and testicular cytology/histology findings.

INTERVENTION(S)

Systematic review of reported men with microdeletions that included eligibility, data extraction and analysis.

MAIN OUTCOME MEASURE(S)

Availability of sperm cells for intracytoplasmic sperm injection (ICSI) in men with AZFb/AZFb-c microdeletions.

RESULT(S)

The average prevalences reported for AZFb, AZFb-c, partial AZFb, and partial AZFb-c in azoospermic men were 0.9%±0.07%, 2.7%±0.93%, 1.23%±0.9%, and 1%±0.6%, respectively. Sperm cells were identified in 7% and 3% of the 28 and 71 men with complete AZFb and AZFb-c and in 57% and 43% of the 14 and 7 men with partial AZFb and AZFb-c deletions, respectively. The likelihood of finding sperm cells in men with complete versus partial AZFb and AZFb-c deletions was significantly lower. As yet, no clinical or chemical pregnancy after ICSI in cases with complete AZFb/b-c microdeletions has been reported.

CONCLUSION(S)

Determining the extent of AZFb or AZFb-c deletions is critical considering the frequency and the reasonable prospect of finding sperm cells in partial AZFb/AZFb-c deletions. Referring men with complete AZFb/b-c microdeletions to testicular sperm extraction/ICSI programs should be revaluated.

The azoospermia factor locus-c region was found to be related to Klinefelter syndrome in Turkish patients

We looked for a possible association between Klinefelter syndrome (KFS) and microdeletions in the Y chromosome in Turkish KFS patients. We examined the frequency of KFS in male patients with proven non-obstructive azoospermia and the types of Y chromosome microdeletions in these KFS patients. Fifty azoospermic patients and 50 fertile men were included in this study. KFS was found in 14 azoospermic patients. Y chromosome microdeletions were found in eight KFS patients. Azoospermia factor locus c (AZFc) was the most commonly deleted interval in KFS patients. All KFS patients had elevated plasma follicle-stimulating hormone and luteinizing hormone concentrations, but they had normal plasma testosterone concentrations. Testis biopsy of five samples with Y microdeletions revealed Sertoli cell-only syndrome. No Y microdeletions were found in the fertile group. We concluded that there could be an association between the AZFc region and KFS. Screening for this should be part of diagnostic work-up, particularly in those considering assisted reproduction.

Oocyte activation, phospholipase C zeta and human infertility

BACKGROUND

Mammalian oocytes are activated by intracellular calcium (Ca(2+)) oscillations following gamete fusion. Recent evidence implicates a sperm-specific phospholipase C zeta, PLCζ, which is introduced into the oocyte following membrane fusion, as the responsible factor. This review summarizes the current understanding of human oocyte activation failure and describes recent discoveries linking certain cases of male infertility with defects in PLCζ expression and activity. How these latest findings may influence future diagnosis and treatment options are also discussed.

METHODS

Systematic literature searches were performed using PubMed, ISI-Web of Knowledge and The Cochrane Library. We also scrutinized material from the United Nations and World Health Organization databases (UNWHO) and the Human Fertilization and Embryology Authority (HFEA).

RESULTS AND CONCLUSIONS

Although ICSI results in average fertilization rates of 70%, complete or virtually complete fertilization failure still occurs in 1-5% of ICSI cycles. While oocyte activation failure can, in some cases, be overcome by artificial oocyte activators such as calcium ionophores, a more physiological oocyte activation agent might release Ca(2+) within the oocyte in a more efficient and controlled manner. As PLCζ is now widely considered to be the physiological agent responsible for activating mammalian oocytes, it represents both a novel diagnostic biomarker of oocyte activation capability and a possible mode of treatment for certain types of male infertility.

Transmissible microdeletion of the Y-chromosome encompassing two DAZ copies, four RBMY1 copies, and both PRY copies

OBJECTIVE

To study a transmissible partial AZFb and -c microdeletion.

DESIGN

Case report.

SETTING

Service of Reproductive Medicine, Molecular Biology, CHU Lyon, France.

PATIENT(S)

A case of oligoasthenospermia with partial spermatogenic failure. Screening for Yq microdeletions revealed the absence of sY143, suggesting an AZFb microdeletion.

INTERVENTION(S)

Sequence-tagged site mapping indicated that the deletion encompassed a portion of the AZFb and -c region. Genomic DNA from the patient's father gave the same pattern. During the course of these investigations, a pregnancy occurred. On the 46,XY amniocyte and cord blood DNA, the same microdeletion was found.

MAIN OUTCOME MEASURE(S)

Study of the fine structure of the Y-chromosome and the gene copy number.

RESULT(S)

The three males of this family have a rearrangement including a deletion encompassing r3 and r4, the palindrome P3, and its boundary regions: u3 and u1 in its distal part. This induced a reduction in DAZ and RBMY1 copy number and complete loss of PRY.

CONCLUSION(S)

PRY is not indispensable to complete spermatogenesis; and with two RBMY1 and two DAZ copies, complete spermatogenesis can be conserved.

In vivoGene Transfer into Testis and Sperm: Developments and Future Application

Despite significant advances in the treatment of infertility via assisted reproductive technology (ART), the underlying causes of idiopathic male infertility still remain unclear. Accumulating evidence suggests that disorders associated with testicular gene expression may play an important role in male infertility. To be able to fully study the molecular mechanisms underlying spermatogenesis and fertilization, it is necessary to manipulate gene expression in male germ cells. Since there is still no reliable method of recapitulating spermatogenesis culture, the development of alternative transgenic approaches is paramount in the study of gene function in testis and sperm. Established methods of creating transgenic animals rely heavily upon injection of DNA into the pronucleus or the injection of transfected embryonic stem cells into blastocysts to form chimeras. Despite the success of these two approaches for making transgenic and knockout animals, concerns remain over costs and the efficiency of transgene integration. Consequently, efforts are in hand to evaluate alternative methodologies. At present, there is much interest in developing approaches that utilize spermatozoa as vectors for gene transfer. These approaches, including testis mediated gene transfer (TMGT) and sperm mediated gene transfer (SMGT), have great potential as tools for infertility research and in the creation of transgenic animals. The aim of this short review is to briefly describe developments in this field and discuss how these gene transfer methods might be used effectively in future research and clinical arenas.

Y CHROMOSOME MICRODELETION IN A CASE WITH KLINEFELTER'S SYNDROME

In male infertility, the frequency of genetic factors is high. Klinefelter's Syndrome is the most frequent sex chromosomal abnormality detected in male infertility. In this study we report a patient diagnosed with Klinefelter's Syndrome with a deletion of the Yq interval. The patient was 24-years old with primary infertility. Semen analyses carried out in triplicate indicated azoospermia. The plasma leutenizing hormone (LH) and follicle stimulating hormone (FSH) levels were abnormally high and the testosterone level was lower than the usual range. Each of his testes had a volume of 3 cc. Peripheral blood karyotype analysis showed Klinefelter's Syndrome (47, XXY) pattern. Polymerase chain reaction amplification of DNA was performed using the following primers; AZFa (sY81, sY82, sY84), AZFb (sY127, sY142, sY164, RBM1), AZFc (CDY, BPY, sY254, sY255, sY277), AZFd (sY152, sY145, sY153). Analysis revealed a single deletion of AZFa region (sY84). Deletion of the AZFa region may be an additional factor for absolute azoospermia in men with Klinefelter's Syndrome. For individuals with Klinefelter's Syndrome who plan to undergo assisted reproduction techniques, Y chromosome microdeletion screening can diagnostically be convenient.

Clinical and laboratory evaluation of idiopathic male infertility in a secondary referral center in India

The genetic basis of infertility has received increasing recognition in recent years, particularly with the advent of assisted reproductive technology. It is now becoming obvious that genetic etiology for infertility is an important cause of disrupted spermatogenesis. Y-chromosome microdeletions and abnormal karyotype are the two major causes of altered spermatogenesis. To achieve biological fatherhood, intracytoplasmic sperm injection (ICSI) is performed in cases of severe infertility with or without genetic abnormalities. There is a concern that these genetic abnormalities can be transmitted to the male progeny, who may subsequently have a more severe phenotype of infertility. A total of 200 men were recruited for clinical examinations, spermiograms, hormonal profiles, and cytogenetic and Yq microdeletion profiles. Testicular biopsy was also performed whenever possible and histologically evaluated. Genetic abnormalities were seen in 7.1% of cases, of which 4.1% had chromosomal aberrations, namely Klinefelter's mosaic (47XXY) and Robertsonian translocation, and 3.0% had Yq microdeletions, which is very low as compared to other populations. Follicle stimulating hormone (FSH) and luteinizing hormone (LH) were significantly increased in men with nonobstructive azoospermia (NOA) as compared to severe oligoasthenozoospermia (P<0.0001), whereas testosterone levels were significantly decreased in men with microdeletions as compared to men with no microdeletions (P<0.0083). Low levels of androgen in men with microdeletions indicate a need to follow-up for early andropause. Patients with microdeletions had more severe testicular histology as compared to subjects without deletions. Our studies showed a significant decrease (P<0.002) in the serum inhibin B values in men with NOA, whereas FSH was seen to be significantly higher as compared to men with severe oligoasthenozoospermia (SOAS), indicating that both the Sertoli cells as well the germ cells were significantly compromised in cases of NOA and partially affected in SOAS. Overall inhibin B in combination with serum FSH would thus be a better marker than serum FSH alone for impaired spermatogenesis. In view of the genetic and hormonal abnormalities in the group of infertile men with idiopathic severe oligozoospermia and NOA cases, who are potential candidates for ICSI, genetic testing for Y-chromosome microdeletions, karyotype, and biochemical parameters is advocated.

Clinical consequences of microdeletions of the Y chromosome: the extended Münster experience

A total of 3179 patients were screened for Y-chromosome microdeletions and 821 patients for partial AZFc deletions. Thirty-nine Y-chromosomal microdeletions were found (2.4% of men with <1 x 10(6)/ml spermatozoa): two AZFa, two AZFb, one AZFbc, one partial AZFb, one partial AZFb+c and 32 AZFc (b2/b4). Partial AZFc deletions were found in 45 patients (5.5%), mostly gr/gr deletions (n = 28). In patients with AZFc deletion, azoospermia was found in 53.1% and sperm concentrations of mostly <0.1 x 10(6)/ml were found in 46.9%. Semen analyses and FSH measurements showed no trend over time. Elongated spermatids were seen in 6/15 AZFc patients and bilateral Sertoli cell-only was found in 4/15. Testicular sperm extraction (TESE) was attempted in 10 patients and spermatozoa were found in six. Compared with infertile men matched by sperm concentration, no differences in hormonal and seminal parameters could be found in patients with AZFc or gr/gr deletions. It is concluded that: (i) frequency of AZF deletions in Germany is much lower than in other countries; (ii) AZFc deletions are associated with severe disturbances of spermatogenesis and TESE is not possible in half of these patients; (iii) AZFc and gr/ gr deletions are not associated with any clinical diagnostic parameter; (iv) and no trend is apparent over time.

Y-chromosomal microdeletions and partial deletions of the Azoospermia Factor c (AZFc) region in normozoospermic, severe oligozoospermic and azoospermic men in Sri Lanka

AIM

To assess for the first time the occurrence of Y chromosomal microdeletions and partial deletions of the Azoospermia Factor c (AZFc) region in Sri Lankan men and to correlate them with clinical parameters.

METHODS

In a retrospective study, we analyzed 96 infertile men (78 with non-obstructive azoospermia) and 87 controls with normal spermatogenesis. AZFa, AZFb, AZFc and partial deletions within the AZFc region were analyzed by multiplex polymerase chain reaction (PCR) according to established protocols.

RESULTS

No AZFa, AZFb or AZFc deletions were found in the control group. Seven patients in the group of infertile men were found to have deletions as following: one AZFa, two AZFc, two AZFbc and two AZFabc. The relative distribution of these patterns was significantly different compared with that found in the German population. Extension analysis confirmed that the deletions occurred according to the current pathogenic model. gr/gr deletions were found to be equally present both in the patients (n=4) and in the control group (n=4). One b2/b3 deletion was found in the patient group.

CONCLUSION

These results suggest that the frequency and pattern of microdeletions of the Y chromosome in Sri Lankan men are similar to those found in other populations and confirm that gr/gr deletions are not sufficient to cause spermatogenetic failure.

Y chromosome microdeletions in azoospermic patients with Klinefelter's syndrome

AIM

To study the occurrence of Y chromosome microdeletions in azoospermic patients with Klinefelter's syndrome (KFS).

METHODS

Blood and semen samples were collected from azoospermic patients with KFS (n = 14) and a control group of men of proven fertility (n = 13). Semen analysis was done according to World Health Organization (WHO) guidelines. Blood samples were processed for karyotyping, fluorescent in situ hybridization (FISH) and measurement of plasma follicle stimulating hormone (FSH) by radioimmunoassay. To determine Y chromosome microdeletions, polymerase chain reaction (PCR) of 16 sequence tagged sites (STS) and three genes (DFFRY, XKRY and RBM1Y) was performed on isolated genomic DNA. Testicular fine needle aspiration cytology (FNAC) was done in selected cases.

RESULTS

Y chromosome microdeletions spanning the azoospermia factor (AZF)a and AZFb loci were found in four of the 14 azoospermic patients with KFS. Karyotype and FISH analysis revealed that, of the four cases showing Y chromosome microdeletion, three cases had a 47,XXY/46,XY chromosomal pattern and one case had a 46,XY/47,XXY/48,XXXY/48,XXYY chromosomal pattern. The testicular FNAC of one sample with Y chromosome microdeletion revealed Sertoli cell-only type of morphology. However, no Y chromosome microdeletions were observed in any of the 13 fertile men. All patients with KFS had elevated plasma FSH levels.

CONCLUSION

Patients with KFS may harbor Y chromosome microdeletions and screening for these should be a part of their diagnostic work-up, particularly in those considering assisted reproductive techniques.

Mutation C677T in the methylenetetrahydrofolate reductase gene is associated with male infertility in an Indian population1

A mutation (C677T) in the gene, MTHFR, is known to increase susceptibility to various multifactorial disorders. In order to assess this single nucleotide polymorphism (SNP) as risk factor for idiopathic male infertility, a case-control study was done on an Indian population. DNA from 151 cases of non-obstruction, idiopathic oligo-/azoospermia and 200 fertile males (controls) was polymerase chain reaction amplified using site-specific primers, and analysed for the mutation following HinfI-digestion. Our results show a significantly increased frequency of CT heterozygotes among infertile patients (p value <0.04). More importantly, while there were no T homozygotes in the control population, six of 151 infertile cases were T homozygous. Considering that T allele occurs in very low frequency in the control population, 677T is clearly a risk factor for infertility in the Indian population. We contend that the same could also be true for African and Southeast Asian populations where the frequency of 677T is very low. The lack of similar association in western populations could be because of the overall dietary enrichment of folates, which could nullify or minimize the effect of this polymorphism.