Sperm Aneuploidy Research Articles

Sperm chromatin dispersion test in the assessment of DNA fragmentation and aneuploidy in human spermatozoa

Sperm DNA damage is thought to be increased in men with male factor infertility. Previous studies suggest a correlation between sperm DNA fragmentation and aneuploidy. The sperm chromatin dispersion (SCD) test was modified to produce the Halosperm Kit. The SCD-fluorescent in-situ hybridization (FISH) test allows the simultaneous detection of DNA fragmentation and aneuploidy on the same sperm cell. The objectives of this study were to validate the SCD, SCD-FISH and Halosperm tests for the analysis of sperm DNA fragmentation and compare them to the sperm chromatin structure assay (SCSA). Semen samples from 20 males undergoing IVF/intracytoplasmic sperm injection were processed using FISH, SCD-FISH, SCD and Halosperm, and compared with SCSA results. There was a significant difference between FISH and SCD-FISH results in the detection of aneuploidy ( P = 0.000) and the level of sperm DNA fragmentation in the samples subjected to SCSA and SCD ( P = 0.001) or SCSA and SCD-FISH ( P = 0.001). There was no significant correlation between DNA fragmentation and aneuploidy. If sperm aneuploidy is to be determined, more reliable results will be obtained if FISH is performed rather than SCD-FISH. A lack of validation and unknown clinical significance question the value of DNA fragmentation assays. DNA damage in the male germ line may result in adverse clinical outcomes and the pathophysiology and clinical consequences of sperm DNA damage are being actively researched. Many DNA fragmentation assays such as the Halosperm Kit have been developed recently and are now available at a commercial level. Unfortunately, aimed at vulnerable couples with difficulty conceiving, many of these tests have not been clinically validated. Despite its plausible appeal and fervour of its supporters, the benefits of widespread DNA testing that only achieves the distressing of couples with the knowledge that effectual therapeutic strategies are absent are questionable. Commercially, however, it is no doubt lucrative. Analysis of gametes prior to the initiation of an IVF cycle may improve the quality of embryos transferred. The clinical and scientific community considers it a matter of urgency to translate the basic science behind how a cell prepares for fertilization into routine clinical practice. However, it is equally important, if not more, to allow the science behind such applications to draw level with its practice before its widespread implementation.

Meiotic recombination errors, the origin of sperm aneuploidy and clinical recommendations

Since the early 1990s male infertility has successfully been treated by intracytoplasmic sperm injection (ICSI), nevertheless concerns have been raised regarding the genetic risk of ICSI. Chromosome aneuploidy (the presence of extra or missing chromosomes) is the leading cause of pregnancy loss and mental retardation in humans. While the majority of chromosome aneuploidies are maternal in origin, the paternal contribution to aneuploidy is clinically relevant particularly for the sex chromosomes. Given that it is difficult to study female gametes investigations are predominantly conducted in male meiotic recombination and sperm aneuploidy. Research suggests that infertile men have increased levels of sperm aneuploidy and that this is likely due to increased errors in meiotic recombination and chromosome synapsis within these individuals. It is perhaps counterintuitive but there appears to be no selection against chromosomally aneuploid sperm at fertilization. In fact the frequency of aneuploidy in sperm appears to be mirrored in conceptions. Given this information this review will cover our current understanding of errors in meiotic recombination and chromosome synapsis and how these may contribute to increased sperm aneuploidy. Frequencies of sperm aneuploidy in infertile men and individuals with constitutional karyotypic abnormalities are reviewed, and based on these findings, indications for clinical testing of sperm aneuploidy are discussed. In addition, the application of single nucleotide arrays for the analysis of meiotic recombination and identification of parental origin of aneuploidy are considered.

Spermatogenesis in Klinefelter syndrome

Klinefelter syndrome (KS) (47,XXY) is the most common sex chromosomal disorder, and it is a frequent form of male hypogonadism and infertility. Although the majority of these patients are azoospermic, they might have severe oligozoospermia or residual single-residual foci with spermatogenesis in the testis. We report our experience on sperm retrieval in the ejaculate and testis, and evaluate the frequency of chromosome abnormalities in sperm of KS. Eighty-four 47,XXY KS were evaluated with seminal analysis, body hair distribution, reproductive hormones, ultrasonographic scanning of the testis and prostate, bilateral testicular sperm extraction (TESE), sperm or testicular cells sex chromosomes aneuploidies. Out of 84 patients, 7 (7/84; 8.3%) had sperm in the ejaculate. Out of the 77 azoospermic patients, 24 underwent TESE and 9 (9/24; 37.5%) had successful sperm recovery. The comparison of reproductive hormones, age and testicular volume did not show significant differences between patients with and without successful sperm recovery in semen or TESE . Patients without successful sperm recovery in semen analysis or TESE had signs of hypoandrogenism more evident than patients with successful sperm recovery. Patients with KS produced a higher number of sperm aneuploidy with respect to normozoospermic fertile controls and non-genetic severely oligozoospermic men. Men with KS are not always sterile. In some of these patients sperm can be found in semen or in the testis, but the proportion of sperm aneuploidy is high. Signs of hypoandrogenism seem to be associated with low sperm recovery rate.

Assessment of acrosome and nuclear abnormalities in human spermatozoa with large vacuoles

Spermatozoa with large vacuoles (SLV) may have a negative impact on embryo development. The origin of these vacuoles is unknown. We evaluated acrosome and nucleus alterations in isolated SLV, versus unselected spermatozoa. We studied 20 patients with teratozoospermia. Spermatozoa from the native semen sample and spermatozoa presenting a vacuole occupying >13.0% total head area, isolated under high magnification (×6600), were assessed. Confocal and transmission electron microscope evaluations were performed on SLV and native sperm, respectively. Acrosome morphology and DNA fragmentation were analysed using proacrosin immunolabelling (monoclonal antibody 4D4) and terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling assay. Chromatin condensation was evaluated with aniline blue staining. Sperm aneuploidy was assessed using fluorescence in situ hybridization. SLV represented 38.0 ± 5.10% of motile spermatozoa obtained after gradient density centrifugation. Vacuoles were mainly in the anterior and median sperm head (45.7 ± 2.90 and 46.1 ± 3.00%, respectively). Abnormal acrosomes were increased in SLV compared with unselected spermatozoa (77.8 ± 2.49 versus 70.6 ± 2.62%; P = 0.014). Microscopic observations showed an exclusively nuclear localization of large vacuoles. Complete DNA fragmentation was higher in native spermatozoa (P < 0.0001) than SLV, while chromatin condensation was altered in SLV (P < 0.0001). Aneuploidy and diploidy rates were increased in SLV (P < 0.0001). Sperm vacuoles were exclusively nuclear. In our selected teratozoospermic population, aneuploidy and chromatin condensation defects were the main alterations observed in SLV. Based on results from this small sample of spermatozoa, we propose a global impairment of the spermatogenesis process as a common origin of the morphological alterations.

Sperm organelle morphologic abnormalities: contributing factors and effects on ICSI outcomes

OBJECTIVE: The goals for this study were to: (i) analyze possible relationships between motile sperm organelle morphology and sperm chromatine status, aneuploidy incidence and patient's age and (ii) determine the effects of sperm morphological abnormalities on intracytoplasmic sperm injection (ICSI) cycles outcomes.DESIGN: Prospective trial.MATERIALS AND METHODS: The study was performed in 50 patients undergoing ICSI cycles. The motile sperm organelle morphology examination (MSOME), sperm DNA fragmentation and sperm aneuploidy incidence were performed in 200 sperm cells of each patient. Regression models were used to assess the relationships between sperm morphology and sperm aneuploidy, sperm DNA fragmentation, patient's age and ICSI outcomes.RESULTS: A close relationship between sperm DNA fragmentation and the presence of vacuoles in the MSOME (R2: 0.067, P = 0.029 for large vacuole and R2: 0.063, P = 0.034 for small vacuoles) was noted. Patient's age was also correlated to the presence of vacuoles (R2: 0.118, P<0.001, for large vacuole and R2: 0.104, P<0.001 for small vacuole). On the other side, no correlation between sperm aneuploidy and sperm morphology was observed. The percentage of normal cells in the MSOME was determinant to the likelihood of fertilization (R2: 0.040, P =0.054), pregnancy (OR: 1.15, P=0.046) and implantation rates (R2: 0.168, P <0.001). When the defects were evaluated individually, it was noted that vacuolated cells was negatively correlated with fertilization, pregnancy and implantation.CONCLUSION: Our data suggest that the selection of sperm for intracytoplasmic injection based on the normal nuclear morphology may be a useful tool to select spermatozoa with intact DNA but not with euploid constitution. Our evidences also suggest a correlation between paternal age and incidence of nuclear vacuoles, as well as an effect of large and small vacuoles on early and late embryo development. OBJECTIVE: The goals for this study were to: (i) analyze possible relationships between motile sperm organelle morphology and sperm chromatine status, aneuploidy incidence and patient's age and (ii) determine the effects of sperm morphological abnormalities on intracytoplasmic sperm injection (ICSI) cycles outcomes. DESIGN: Prospective trial. MATERIALS AND METHODS: The study was performed in 50 patients undergoing ICSI cycles. The motile sperm organelle morphology examination (MSOME), sperm DNA fragmentation and sperm aneuploidy incidence were performed in 200 sperm cells of each patient. Regression models were used to assess the relationships between sperm morphology and sperm aneuploidy, sperm DNA fragmentation, patient's age and ICSI outcomes. RESULTS: A close relationship between sperm DNA fragmentation and the presence of vacuoles in the MSOME (R2: 0.067, P = 0.029 for large vacuole and R2: 0.063, P = 0.034 for small vacuoles) was noted. Patient's age was also correlated to the presence of vacuoles (R2: 0.118, P<0.001, for large vacuole and R2: 0.104, P<0.001 for small vacuole). On the other side, no correlation between sperm aneuploidy and sperm morphology was observed. The percentage of normal cells in the MSOME was determinant to the likelihood of fertilization (R2: 0.040, P =0.054), pregnancy (OR: 1.15, P=0.046) and implantation rates (R2: 0.168, P <0.001). When the defects were evaluated individually, it was noted that vacuolated cells was negatively correlated with fertilization, pregnancy and implantation. CONCLUSION: Our data suggest that the selection of sperm for intracytoplasmic injection based on the normal nuclear morphology may be a useful tool to select spermatozoa with intact DNA but not with euploid constitution. Our evidences also suggest a correlation between paternal age and incidence of nuclear vacuoles, as well as an effect of large and small vacuoles on early and late embryo development.

Rise in sperm aneuploidy rate "slight" after chemo

Rise in sperm aneuploidy rate "slight" after chemo

Sperm head birefringence selection and aneuploidy

OBJECTIVE: The selection of sperm head birefringence (SHBF) has been proposed to improve ICSI outcomes. Published studies have shown that the injection that injection of spermatozoa with partial SHBF improves the development of viable embryos and rates of implantation and pregnancy in ICSI cycles. On the other hand, sperm aneuploidy is associated with ICSI failure, pregnancy loss and aneuploid conceptions. The objective of this study was to evaluate the relationship between human SHBF subtypes and sperm aneuploidy.

Effects of anti-neoplastic treatment on sperm aneuploidy rate in patients with testicular tumor: A longitudinal study

The adjuvant radio/chemotherapy, usually employed after orchidectomy in patients with testicular tumors, allows a long-term survival with a consequent increased request for fertility. However, little is known about the effects of the anti-neoplastic treatment on sperm cytogenetic asset. Therefore, this prospective, longitudinal study was designed to evaluate the effects of radio- and/or chemotherapy on sperm chromosome. Eleven patients with testicular tumor were enrolled and underwent sperm aneuploidy rate evaluation before and after 3, 6, 9, 12, 18, 24, and 36 months from radio- and/or chemo-therapy ending. A double and triple multicolor fluorescence in-situ hybridizations for chromosomes 8, 12, 18, X and Y were used to evaluate the sperm aneuploidy rate. To define normal sperm aneuploidy rate, 18 healthy, normozoospermic men were selected as controls. Before treatment, testicular tumor patients had a higher total sperm aneuploidy rate compared with normal men. Total sperm aneuploidy rate showed a slight, but statistically significant increase 6 months after anti-neoplastic treatment. This increase was mainly related to the high sperm aneuploidy rate found in 2 patients which remained elevated up to 12 months in both of them. These results showed that anti-neoplastic treatment caused only slight and transient sperm malsegregation events in patients with testicular tumor. However, since a subset of them had an elevated sperm aneuploidy rate for about 1 yr, we suggest to counsel them to refrain from fatherhood for this length of time.

Fertile bull sperm aneuploidy and chromatin integrity in relationship to fertility

Aneuploidy is associated with spontaneous abortions, perinatal mortality, mental retardation and with embryonic and foetal mortality. Most of these abnormalities originate as a result of meiosis errors during gametogenesis. The main purpose of the study was to analyse frequency of aneuploidies of sex chromosomes and chromosome 6 by three-colour fluorescence in situ hybridization (FISH) in 47 young bulls, candidates for artificial insemination programme with cryopreserved semen and to investigate the influence of aneuploidies and disturbed sperm chromatin integrity on non-return rates, the frequencies of abortions, perinatal mortality and stillbirths. The average frequencies of spermatozoa with disomy for chromosomes X, Y, XY and 6 were 0.032, 0.005, 0.003 and 0.039% respectively. The incidence of XX66, YY66 and XY66 diploidy was 0.017, 0.006 and 0.015% respectively. Frequencies of meiotic II errors were significantly higher than meiotic I errors (p < 0.01). More X bearing spermatozoa than Y bearing spermatozoa were detected (5151 vs. 5022; p < 0.01). Sperm chromatin damage expressed by DNA fragmentation index (DFI) was 5.3 +/- 3.7 and percentage of cells with defective chromatin condensation (HDS) was 1.4 +/- 0.8. No correlation was found between sperm aneuploidy and basic sperm analysis. The relationship was found between non-return rate and total aneuploidy (r = -0.310; p = 0.036). Significant correlation was found between sex disomy, total aneuploidy (disomy of chromosomes 6, X, Y and XY spermatozoa and diploidy) and stillbirths (r = 0.390; p = 0.013; and r = 0.331; p = 0.037). Chromosome 6 disomy correlated with perinatal mortality (r = 0.317; p = 0.047). HDS correlated significantly with total aneuploidy (r = 0.449; p = 0.002). Our study indicated that aneuploidy frequencies in young fertile bull spermatozoa are relatively low. Nevertheless, there exists a variability in aneuploidy frequencies amongst bulls, which appears to be able to have an influence on the fertility of these animals.

The use of fluorescent in situ hybridization in male infertility

Male factors are implicated in up to 50% of couples being evaluated and treated for infertility with advanced assisted reproductive technologies. Genetic abnormalities, including sperm chromosome aneuploidy as well as structural aberrations, are one of the major causes of infertility. The use of chromosome-specific DNA probes labeled with fluorochromes, particularly the combination with multiple probes, has been used to indirectly study the sperm chromosome by fluorescent in situ hybridization (FISH). Clinically, this technique is also used to assess the sperm of men recovering from gonadotoxic treatment. Recent advances in this technology facilitate the evaluation of sperm aneuploidy. Sperm FISH is a widely used screening tool to aid in counseling couples with severe male factor infertility, especially in cases of prior repeated in vitro fertilization/intracytoplasmic sperm injection failure or recurrent pregnancy loss. Automation of FISH imaging and analysis, as well as the development of emerging techniques such as comparative genomic hybridization, will all contribute to the promise of future diagnostic approaches aimed at improving the quality, ease, and efficiency of aneuploidy analysis.

Genomics revolution on andrology: genetic testing for male infertility

Dear Editor, We would like to write to you on the era of 'omics—genomics revolution on andrology, the way that has taken into a new dimension for tackling the emerging pressure on male infertility and for normal successful fertility outcome. In the Special Issue on Semen Analysis of Asian Journal of Andrology, Aitken 1 has extensively discussed the causes of male infertility, the past and the future developmental methods for its treatment and possible modes of prevention have been. The author stated that in the 21st century, molecular andrologists will have wide range of methods to examine the defective spermatozoa of infertile patients. We would like to present the supporting data on sperm chromosomal abnormalities in infertile men and their implications on fertility. Abnormal semen parameters in chromosomally normal men are an indicator of an increased risk of sperm aneuploidy 2. These authors found the meiotic segregation and an interchromosomal effect in carriers of (11;18) by multicolor fluorescence in situ hybridization (FISH). They concluded that FISH analysis provides useful information for genetic counseling and assisted reproduction. The risk of male's sperm aneuploidy used for intracytoplasmic sperm injection (ICSI) needs to be evaluated to prevent the further aneuploidy in the offspring of these men. Some studies 3, 4 revealed that the infertile men with normal karyotypes possessed higher frequency of sperm aneuploidy, specifically the sex chromosomes. Male carriers of Robertsonian translocations are vulnerable for fertility problems as evident from 14 Robertsonian carriers 5. We also observed the similar findings as evident from the above mentioned literature with respect to the chromosomal pattern, translocations and sperm chromosomal (Y chromosome) microdeletions in our tertiary referral hospital, All India Institute of Medical Sciences, New Delhi, India. Hence evaluation of spermatozoa with different techniques, such as single cell gel electrophoresis (COMET assay), terminal transferase dUTP Nick End Labeling (TUNEL), sperm chromatin structure assay (SCSA), in situ nick translation (ISNT), acridine orange test, germ cell chromosomal aneuploidies and microdeletions, will help detecting the defecfective spermatozoa in men opting for assisted reproduction 6, 7, 8, 9, 10, 11, 12, 13. Preimplantation genetic diagnosis is an added new promising approach at the molecular level with the application of polymerase chain reaction (PCR)-based protocols. These protocals are carried out for translocation analysis utilizing multiplexed short tandem repeat (STR) markers located on both segments of the translocated chromosomes 14. When the need arises for in vitro fertilization (IVF)/ICSI for the treatment of male infertility, the use of the above mentioned cytomolecular diagnostic tests may be taken into consideration with proper consent of the subject. This molecular diagnostic approach will enable us to study the integrity of the sperm DNA because it is the essential and prerequisite criteria for the accurate transmission of genetic material from parents to offspring.

C30 Clinical relevance of male meiosis and sperm aneuploidy

C30 Clinical relevance of male meiosis and sperm aneuploidy

P17 Sperm and lymphocyte aneuploidy in patients with translocations

P17 Sperm and lymphocyte aneuploidy in patients with translocations

P11 Sperm aneuploidy: When to stop counting?

P11 Sperm aneuploidy: When to stop counting?

Array comparative genomic hybridization (CGH) analysis of sperm DNA to detect copy number variations in infertile men with idiopathic azoospermia

Epididymal and testicular spermatozoa of azoospermic patients are frequently used for intracytoplasmic sperm injection (ICSI), so they must be screened for genetic abnormalities. The objective of our study was to investigate whole genome imbalances in immature germ cells found in ejaculates of six males with idiopathic azoospermia and normal karyotype. We used for the first time the most powerful tool for genetic screening - microarray-based technology of comparative genomic hybridization (array CGH) with microarrays, covering all autosomes and sex-chromosomes at a mean density of 1 BAC clone/0.5 Mb. Sub-microscopic copy number variations were found in sperm DNA of all analyzed patients. The most consistent were aberrations in Y-chromosome - they occurred in 5 out of 6 patients (83.3%). These Y micro-aberrations included both micro-deletions and micro-duplications. In addition to Y chromosomal micro-imbalances, we detected several other affected loci. These included 1N€36 deletion together with 14q24 gain, 16q24 deletion, 9q34 gain and 3q29 deletion. By array CGH analysis we determined cryptic whole genome imbalances in sperm cells and defined the most precisely the size and the boundaries of aberrations. Key words: Male infertility, azoospermia, sperm aneuploidy, whole genome analysis, array CGH.

Benzene Exposure Near the U.S. Permissible Limit Is Associated with Sperm Aneuploidy

BackgroundBenzene is a common industrial chemical known to induce leukemia and other blood disorders, as well as aneuploidy, in both human blood cells and sperm at exposures > 10 ppm. Recent reports have identified health effects at exposure levels < 1 ppm, the permissible exposure limit (PEL; 8 hr) set by the U.S. Occupational Safety and Health Administration.ObjectiveWe investigated whether occupational exposures to benzene near 1 ppm induce aneuploidy in sperm.MethodsWe used multicolor fluorescence in situ hybridization to measure the incidence of sperm with numerical abnormalities of chromosomes X, Y, and 21 among 33 benzene-exposed men and 33 unexposed men from Chinese factories. Individual exposures were assessed using personal air monitoring and urinary concentrations of benzene and trans,trans-muconic acid (E,E-MA). Air benzene concentrations were not detectable in unexposed men; in exposed men, concentrations ranged from below the detection limit to 24 ppm (median, 2.9 ppm), with 27% of exposed men (n = 9) having concentrations of ≤ 1 ppm. Exposed men were categorized into low and high groups based on urinary E,E-MA (median concentrations of 1.9 and 14.4 mg/L, respectively; median air benzene of 1 and 7.7 ppm, respectively), and aneuploidy frequencies were compared with those of unexposed men.ResultsSperm aneuploidy increased across low- and high-exposed groups for disomy X [incidence rate ratio (IRR) = 2.0; 95% confidence interval (CI), 1.1–3.4; and IRR = 2.8; 95% CI, 1.5–4.9, respectively], and for overall hyperhaploidy for the three chromosomes investigated (IRR = 1.6; 95% CI, 1.0–2.4; and IRR = 2.3; 95% CI, 1.5–3.6, respectively). We also found elevated disomy X and hyperhaploidy in the nine men exposed to ≤ 1 ppm benzene compared with unexposed men (IRR = 1.8; 95% CI, 1.1–3.0; and IRR = 2.0; 95% CI, 1.1–3.9, respectively).ConclusionsBenzene appeared to increase the frequencies of aneuploid sperm for chromosomes associated with chromosomal abnormality syndromes in human offspring, even in men whose air benzene exposure was at or below the U.S. permissible exposure limit.

Benzene Exposure Near the U.S. Permissible Limit Is Associated with Sperm Aneuploidy

Benzene Exposure Near the U.S. Permissible Limit Is Associated with Sperm Aneuploidy

Scoring of sperm chromosomal abnormalities by manual and automated approaches: qualitative and quantitative comparisons

It is now well known that levels of sperm disomy correlate to levels of infertility (as well as other factors). The risk of perpetuating aneuploidy to the offspring of infertile males undergoing intracytoplasmic sperm injection (ICSI) has become a hotly debated issue in assisted reproduction; however, there remain barriers to the practical implementation of offering sperm disomy screening in a clinical setting. The major barrier is the operator time taken to analyze a statistically meaningful (sufficient) number of cells. The introduction of automated 'spot counting' software-hardware combinations presents a potential solution to this problem. In this preliminary validation study, we analyzed 10 patients, both manually and using a commercially available spot counter. Results show a statistically significant correlation between both approaches for scoring of sperm disomy, but no correlation is found when scoring for diploid sperm. The most likely explanation for the latter is an apparent overscoring of two closely associated sperm heads as a single diploid cell. These results, and similar further studies that will ensue, help to inform cost-benefit analyses that individual clinics need to carry out in order to decide whether to adopt sperm aneuploidy screening as a routine tool for the assessment of sperm from men requiring ICSI treatment.

X-Y Sperm Aneuploidy in 2 Cattle (Bos taurus) Breeds as Determined by Dual Color Fluorescent in situ Hybridization (FISH)

The present study was undertaken to investigate aneuploidy rates in the sperm populations of 2 cattle (Bos taurus) breeds by using dual color fluorescent in situ hybridization (FISH) with Xcen and Y chromosome-specific painting probes, obtained by chromosome microdissection and DOP-PCR. Frozen semen from 10 Italian Friesian and 10 Italian Brown testing bulls was used for the investigation. For each bull, more than 5,000 sperm were analyzed, for a total of 52,586 and 51,342 sperm cells for the 2 breeds, respectively. The present study revealed – in both breeds – a preponderance of the Y-bearing sperm compared to the X-bearing sperm. Within each breed, a statistically significant variation in the various classes of aneuploidy (XX, YY and XY) was found: differences were found in the Friesian breed among the 3 diploidy classes, and in the Brown breed, among the 3 disomy classes (p < 0.05) as well as among the 3 diploidy classes (p < 0.01). However, the 2 breeds did not differ significantly in the overall mean rates of X-Y aneuploidy (disomy + diploidy) which amounts to 0.162% in the Italian Friesian and 0.142% in the Italian Brown. When meiosis I (MI) and II (MII) errors were compared, statistically significant differences (p < 0.01) were found in the disomy classes and in both breeds, whereas the differences between diploidy classes were not significant. Compared to humans, a lower level of aneuploidy has been found in the domestic species analyzed so far. The present study contributes to the establishment of a baseline level of aneuploidy in the sperm populations of 2 cattle breeds which could be used for monitoring future trends of reproductive health, especially in relation to environmental changes and mutagens.

Association between sperm DNA fragmentation and aneuploidy rate in assisted reproduction patients

OBJECTIVE: Damage to sperm chromatin, such as DNA fragmentation that has been associated with male infertility, unsuccessful conception and poor sustained pregnancy. However few studies have shown that fragmented DNA can be associated with chromosomal aberrations in sperm. Therefore the aim of this study was to analyze the frequency of sex-chromosomal aneuploidy in spermatozoa of non-fragmented (NF) and fragmented (F) assisted reproduction treatment (ART) patients, and to correlate aneuploidy rate between each group. DESIGN: Prospective laboratory study. MATERIALS AND METHODS: Sperm DNA fragmentation rate (SDFR) was assessed by sperm chromatin dispersion (SCD) test and patients were divided in NF (SDFR ≤16%) and F (SDFR>16%). Aneuploidy rate evaluated by Fluorescence in situ hybridization (FISH) with direct label probes specific for chromosome 18, X and Y (Kreatech Diagnosis, Netherlands). A total of 500 spermatozoa were analyzed per sample. Statistical analysis was performed with Mann-Whitney test (median; range), Spearman's correlation test and binary logistic regression. Every calculation was done by Graph Pad Prism 4 program. RESULTS: Twenty samples from ART patients were assigned to F (n=10) and NF (n=10). The rate of gonosomal aneuploidy was lower in NF (11.5; 5-43) than in F (28; 14-56; P<0.05). Likelihood for aneuploidy in spermatozoa DNA is 2-fold increased in men with fragmented sperm DNA (odds ratio: 2.01; 95% confidence interval=1.6-2.4; p<0.001). Aneuploidy rate and fragmentation of sperm DNA were significantly correlated (r=0.56; P<0.01). CONCLUSIONS: Sperm DNA fragmentation is strongly correlated to aneuploidy rate and may be a consequence of aneuploidy during sperm maturation. Additionally our findings suggest that males with fragmented sperm DNA have risk of fathering aneuploid offspring.