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Human Reproduction (Oxford, England) Aug 2021What are the causative genetic variants in patients with male infertility due to severe sperm motility disorders?
STUDY QUESTION
What are the causative genetic variants in patients with male infertility due to severe sperm motility disorders?
SUMMARY ANSWER
We identified high confidence disease-causing variants in multiple genes previously associated with severe sperm motility disorders in 10 out of 21 patients (48%) and variants in novel candidate genes in seven additional patients (33%).
WHAT IS KNOWN ALREADY
Severe sperm motility disorders are a form of male infertility characterised by immotile sperm often in combination with a spectrum of structural abnormalities of the sperm flagellum that do not affect viability. Currently, depending on the clinical sub-categorisation, up to 50% of causality in patients with severe sperm motility disorders can be explained by pathogenic variants in at least 22 genes.
STUDY DESIGN, SIZE, DURATION
We performed exome sequencing in 21 patients with severe sperm motility disorders from two different clinics.
PARTICIPANTS/MATERIALS, SETTING, METHOD
Two groups of infertile men, one from Argentina (n = 9) and one from Australia (n = 12), with clinically defined severe sperm motility disorders (motility <5%) and normal morphology values of 0-4%, were included. All patients in the Argentine cohort were diagnosed with DFS-MMAF, based on light and transmission electron microscopy. Sperm ultrastructural information was not available for the Australian cohort. Exome sequencing was performed in all 21 patients and variants with an allele frequency of <1% in the gnomAD population were prioritised and interpreted.
MAIN RESULTS AND ROLE OF CHANCE
In 10 of 21 patients (48%), we identified pathogenic variants in known sperm assembly genes: CFAP43 (3 patients); CFAP44 (2 patients), CFAP58 (1 patient), QRICH2 (2 patients), DNAH1 (1 patient) and DNAH6 (1 patient). The diagnostic rate did not differ markedly between the Argentinian and the Australian cohort (55% and 42%, respectively). Furthermore, we identified patients with variants in the novel human candidate sperm motility genes: DNAH12, DRC1, MDC1, PACRG, SSPL2C and TPTE2. One patient presented with variants in four candidate genes and it remains unclear which variants were responsible for the severe sperm motility defect in this patient.
LARGE SCALE DATA
N/A.
LIMITATIONS, REASONS FOR CAUTION
In this study, we described patients with either a homozygous or two heterozygous candidate pathogenic variants in genes linked to sperm motility disorders. Due to unavailability of parental DNA, we have not assessed the frequency of de novo or maternally inherited dominant variants and could not determine the parental origin of the mutations to establish in all cases that the mutations are present on both alleles.
WIDER IMPLICATIONS OF THE FINDINGS
Our results confirm the likely causal role of variants in six known genes for sperm motility and we demonstrate that exome sequencing is an effective method to diagnose patients with severe sperm motility disorders (10/21 diagnosed; 48%). Furthermore, our analysis revealed six novel candidate genes for severe sperm motility disorders. Genome-wide sequencing of additional patient cohorts and re-analysis of exome data of currently unsolved cases may reveal additional variants in these novel candidate genes.
STUDY FUNDING/COMPETING INTEREST(S)
This project was supported in part by funding from the Australian National Health and Medical Research Council (APP1120356) to M.K.O.B., J.A.V. and R.I.M.L., The Netherlands Organisation for Scientific Research (918-15-667) to J.A.V., the Royal Society and Wolfson Foundation (WM160091) to J.A.V., as well as an Investigator Award in Science from the Wellcome Trust (209451) to J.A.V. and Grants from the National Research Council of Argentina (PIP 0900 and 4584) and ANPCyT (PICT 9591) to H.E.C. and a UUKi Rutherford Fund Fellowship awarded to B.J.H.
Topics: Australia; Exome; Humans; Infertility, Male; Male; Sperm Motility; Sperm Tail; Spermatozoa; Exome Sequencing
PubMed: 34089056
DOI: 10.1093/humrep/deab099 -
Frontiers in Cell and Developmental... 2020With the continued steep rise of the global human population, and the paucity of safe and practical contraceptive options available to men, the need for development of... (Review)
Review
With the continued steep rise of the global human population, and the paucity of safe and practical contraceptive options available to men, the need for development of effective and reversible non-hormonal methods of male fertility control is widely recognized. Currently there are several contraceptive options available to men, however, none of the non-hormonal alternatives have been clinically approved. To advance progress in the development of a safe and reversible contraceptive for men, further identification of novel reproductive tract-specific druggable protein targets is required. Here we provide an overview of genes/proteins identified in the last decade as specific or highly expressed in the male reproductive tract, with deletion phenotypes leading to complete male infertility in mice. These phenotypes include arrest of spermatogenesis and/or spermiogenesis, abnormal spermiation, abnormal spermatid morphology, abnormal sperm motility, azoospermia, globozoospermia, asthenozoospermia, and/or teratozoospermia, which are all desirable outcomes for a novel male contraceptive. We also consider other associated deletion phenotypes that could impact the desirability of a potential contraceptive. We further discuss novel contraceptive targets underscoring promising leads with the objective of presenting data for potential druggability and whether collateral effects may exist from paralogs with close sequence similarity.
PubMed: 32161754
DOI: 10.3389/fcell.2020.00061 -
Theranostics 2021Idiopathic asthenozoospermia (iAZS) is one of the major causes of male infertility and has no effective therapeutic treatment. Understanding the potential mechanisms...
Idiopathic asthenozoospermia (iAZS) is one of the major causes of male infertility and has no effective therapeutic treatment. Understanding the potential mechanisms that cause it may be helpful in seeking novel targets and treatment strategies for overcoming the problem of low sperm motility in iAZS individuals. Computer-assisted semen analysis (CASA) was utilized to assess the sperm motility. RT-qPCR, Western blot, immunofluorescence staining, and calcium imaging analysis were performed to examine the expression and function of CatSper channels. Hyperactivation and acrosome reaction were used to evaluate the functional characteristics of epididymal sperm. fertility assay was applied to determine the fertility of rats. CatSper1 knockdown and overexpression experiments were performed to confirm the roles of CatSper channels in the pathogenesis of iAZS and the therapeutic effects of electroacupuncture (EA) treatment on AZS model rats. Here, we reported a functional down-regulation of CatSper channel from CatSper1 to CatSper 4 in the sperm of both iAZS patients and ornidazole (ORN)-induced AZS model rats, and an impaired sperm function characterized by a reduction of protein tyrosine phosphorylation, hyperactivation, and acrosome reaction in the epididymal sperm of AZS rats. Knockdown of CatSper1 in the testis tissues is sufficient to induce AZS in normal rats, and this action was validated by the reversal effects of CatSper1 overexpression. Transcutaneous electrical acupoint stimulation (TEAS) and electroacupuncture (EA) at 2 Hz frequency improve the sperm motility via enhancing the functional expression of CatSper channels in the sperm. Gene silencing in the sperm abolishes the therapeutic effects of 2 Hz-EA treatment on AZS rats. We conclude that a functional down-regulation of CatSper channel in the sperm may be a contributor or a downstream indicator for a portion of AZS, especially iAZS, while 2 Hz-TEAS or EA treatment has a therapeutic effect on iAZS through inducing the functional up-regulation of CatSper channels in the sperm. This study provides a novel mechanism for the pathogenesis of some AZS especially iAZS, and presents a potential therapeutic target of CatSper for iAZS treatment. Acupuncture treatment like TEAS may be used as a promising complementary and alternative medicine (CAM) therapy for male infertility caused by iAZS in clinical practice.
Topics: Acrosome Reaction; Acupuncture Therapy; Adult; Animals; Asthenozoospermia; Calcium Channels; Down-Regulation; Humans; Male; Middle Aged; Rats; Sperm Motility; Spermatozoa; Young Adult
PubMed: 33456575
DOI: 10.7150/thno.51869 -
Journal of Endocrinological... Jul 2021No data are currently available on the implication of amicrobial leukocytospermia in male adolescents. Therefore, the primary aim of this study was to evaluate the...
BACKGROUND
No data are currently available on the implication of amicrobial leukocytospermia in male adolescents. Therefore, the primary aim of this study was to evaluate the prevalence of amicrobial leukocytospermia among non-smoker late adolescents who were exposed to other risky lifestyles for the andrological health. The main andrological clinical features of adolescents with leukocytospermia were also reported.
METHODS
This is a cross-sectional study carried out in 80 boys. Each adolescent underwent a physical examination, and to the assessment of sperm conventional parameters, seminal leukocytes concentration and immature germ cell evaluation. A possible correlation between seminal leukocytes and immature germ cells and testicular volume (TV) was tested.
RESULTS
The adolescents enrolled in this study had 18.0 ± 0.4 (range 18.1-18.9) years. Unprotected sexual intercourse was referred by 38% of them. Sexual dysfunctions were found in 25% and isolated hypoactive sexual desire in 12.5% of boys. Low TV and penile length in flaccidity were found in 44% and 30% of them, respectively. Only 41% had normozoospermia at the sperm analysis, whereas 19% had isolated oligozoospermia, 15% oligo-asthenozoospermia, and 25% oligo-astheno-teratozoospermia. Leukocytospermia occurred in 25% (20 out of 80) of adolescents. No seminal infection was detected in 19% (15 out of 80) of them. Adolescents with leukocytospermia had lower progressive sperm motility, percentage of normal forms, TV, and a higher percentage of immature germ cells compared to those without leukocytospermia. Semen leukocyte concentration correlated negatively with TV and positively with the percentage of immature germ cells in the ejaculate.
CONCLUSION
Leukocytospermia, increased immature germ cell number, and low TV identify a distinct phenotype suggestive of testicular tubulopathy. Primary prevention of male infertility and the counselling for andrological risky lifestyles is mandatory and should be started as early as possible.
Topics: Adolescent; Cross-Sectional Studies; Follow-Up Studies; Humans; Infertility, Male; Italy; Leukocytes; Leukocytosis; Leukopenia; Male; Prognosis; Semen; Spermatozoa
PubMed: 33226627
DOI: 10.1007/s40618-020-01462-8 -
Andrology Jan 2023The cellular and molecular mechanisms of the events that help spermatozoa acquire their fertilizing capability during capacitation and acrosome reaction are not...
BACKGROUND
The cellular and molecular mechanisms of the events that help spermatozoa acquire their fertilizing capability during capacitation and acrosome reaction are not completely understood.
OBJECTIVE
This study was performed with a postulation that the identification of sperm proteins and their changes during in vitro capacitation and acrosome reaction will unravel unknown molecular aspects of fertilization that impact male fertility.
MATERIALS AND METHODS
Spermatozoa collected from sequential conditions, that is, separation of ejaculated spermatozoa by Percoll gradient centrifugation, in vitro capacitation, and acrosome reaction were processed for tandem mass spectrometric analysis, followed by protein identification, label-free quantitation, and statistical analysis.
RESULTS AND DISCUSSION
Collectively, a total of 1088 sperm proteins were identified. In comparison to ejaculated spermatozoa, 44 and 141 proteins were differentially expressed in capacitated and acrosome reacted spermatozoa, respectively. A large number of proteins were found downregulated, including clusterin, pyruvate dehydrogenase E1 component, semenogelin-1 and 2, heat shock protein 90, beta-microseminoprotein, and keratin. It was expected as sperm-membrane-associated proteins are removed during capacitation. There were significant proteomic alterations in asthenozoospermia compared to normozoospermia; however, variation was more noticeable among proteins of acrosome reacted spermatozoa and those released during the acrosome reaction. The processes enriched among downregulated proteins in asthenozoospermia included acrosome assembly, binding of spermatozoa to zona pellucida, nucleosome assembly, flagellated sperm motility, protein folding, oxidative phosphorylation, tricarboxylic acid cycle, chromatin silencing, gluconeogenesis, glycolytic process, and glycolysis.
CONCLUSION
The dynamic information generated about proteomic alterations in spermatozoa during capacitation and acrosome reaction and their variability in asthenozoospermia will contribute not only to enhancing our understanding of processes that prepare spermatozoa to acquire fertilization capability but also help in deciphering novel factors of male infertility.
Topics: Male; Humans; Acrosome Reaction; Sperm Capacitation; Asthenozoospermia; Sperm Motility; Proteomics; Semen; Spermatozoa; Acrosome
PubMed: 36057948
DOI: 10.1111/andr.13289 -
Reproduction & Fertility Apr 2022Sperm motility varies between ejaculates from different men and from individual men. We studied normozoospermic and asthenozoospermic ejaculates after density-gradient...
UNLABELLED
Sperm motility varies between ejaculates from different men and from individual men. We studied normozoospermic and asthenozoospermic ejaculates after density-gradient centrifugation washing (DCG, 80/40%) and compared high- (80%) and low (40%)-motility sperm populations within the same sample. Our objective was to identify differences in endogenous metabolomes and energy metabolism in relation to sperm motility. H-Nuclear Magnetic Resonance spectroscopy (NMR) measured the endogenous metabolome of live human sperm. Incubating sperm with C-labelled substrates detected energy metabolism by C-NMR. The study examined 850 ejaculates and diagnosed asthenozoospermia in 6.1%. DGC was used to wash 160 normozoospermic (N) and 52 asthenozoospermic (A) ejaculates to recover high-motility sperm from the pellet (80N/80A) and low motility from the interface (40N/40A). H-NMR spectra, 45(N) and 15(A), were binned and the integrals normalised by sperm concentration. Sperm from 126(N) and 36(A) ejaculates were incubated with either C-glucose, C-fructose or C-pyruvate. C-NMR lactate and bicarbonate integrals were normalised by motile or vital sperm concentrations. H-NMR spectra choline integrals from the 80A population were significantly lower than the 80N, < 0.0001. C-substrate conversion to lactate was significantly higher for 40A sperm than 80A sperm when normalised by motile sperm concentration. Bicarbonate integrals were sporadically observed. Sperm from asthenozoospermic ejaculates had similar glycolytic requirements to normozoospermic ones, with larger differences observed between 40 and 80% sperm populations. Higher lactate levels produced by 40% sperm may indicate that impaired sperm motility is due to dysregulated energy metabolism. The alteration in choline metabolism provides opportunities to understand the aetiology of asthenozoospermia.
LAY SUMMARY
How well sperm swim (motility) varies between ejaculates from different men? Normal sperm motility is beneficial to conception and some men diagnosed with infertility have low sperm motility. Sperm metabolise molecules to produce the energy required for motility. We measured concentrations of molecules within sperm and metabolism of molecules given to sperm and related these to the proportion of motile sperm. The study examined 850 sperm samples and found low motility in 6.1%. Metabolism of molecules given to sperm was similar between low and normal motility sperm samples. However, when the most motile sperm were separated from the rest, they were more efficient in metabolising these molecules to achieve motility. Lower concentrations of a molecule called choline were found in low-motility sperm samples compared to normal samples. Choline is associated with cell membranes, energy metabolism and oxidative stress, which may give opportunities to understand the causes of low motility.
Topics: Asthenozoospermia; Bicarbonates; Choline; Humans; Lactates; Magnetic Resonance Spectroscopy; Male; Semen; Sperm Motility; Spermatozoa
PubMed: 35514541
DOI: 10.1530/RAF-21-0101 -
Asian Journal of Andrology 2022Large numbers of microbes can be present in seminal fluid, and there are differences in the semen microbiota between normal and abnormal semen samples. To evaluate the...
Large numbers of microbes can be present in seminal fluid, and there are differences in the semen microbiota between normal and abnormal semen samples. To evaluate the semen microbiota in patients with leukocytospermia, 87 seminal fluid samples, including 33 samples with a normal seminal leukocyte count and 54 samples with leukocytospermia, were obtained for a cross-sectional analysis. Twenty samples with a normal seminal leukocyte count had normal sperm parameters (Control group), and 13 samples with a normal seminal leukocyte count were from asthenozoospermia patients (Ast group). However, 32 samples with leukocytospermia were from asthenozoospermia patients (LA group), and only 22 samples with leukocytospermia had normal sperm parameters (Leu group). The 16S ribosomal RNA (rRNA) gene sequencing method was used to sequence the microbiota in the seminal fluid, and multiple bioinformatics methods were utilized to analyze the data. Finally, the results showed that the worse sperm parameters were observed in the leukocytospermia-related groups. Semen microbiota analysis found that there was increased alpha diversity in the leukocytospermia-related groups. Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes were the primary phyla in the seminal fluid. Two microbiota profiles, namely, Lactobacillus-enriched and Streptococcus-enriched groups, were identified in this study. The majority of the samples in the groups with a normal seminal leukocyte count could be categorized as Lactobacillus-enriched, whereas the majority of the leukocytospermia samples could be categorized as Streptococcus-enriched. Our study indicated that males with leukocytospermia have worse sperm parameters and a different semen microbiota composition compared to males with a normal seminal leukocyte count.
Topics: Asthenozoospermia; Cross-Sectional Studies; Humans; Infertility, Male; Male; Microbiota; Semen; Spermatozoa
PubMed: 34916474
DOI: 10.4103/aja202172 -
The World Journal of Men's Health Oct 2022The protein encoded by dynein axonemal heavy chain 1 () is a part of dynein, which regulates the function of cilia and sperm flagella. The mutant of causes the deletion... (Review)
Review
The protein encoded by dynein axonemal heavy chain 1 () is a part of dynein, which regulates the function of cilia and sperm flagella. The mutant of causes the deletion of inner dynein arm 3 in the flagellum, leading to multiple morphological abnormalities of the sperm flagella (MMAF) and severe asthenozoospermia. However, instead of asthenozoospermia and MMAF, the result caused by the mutation of remains unknown. Here we report a male infertility patient with severe asthenozoospermia and teratozoospermia. We found two heterozygous mutations in (c.6912C>A and c.7076G>T) and which were reported to be associated with MMAF for the first time. We next collected and analyzed 65 cases of mutation and found that the proportion of short flagella is the largest, while the bent flagella account for the smallest, and the incidence of head deformity is not high in the sperm of these patients. Finally, we also analyzed 31 mutation patients who were treated with intracytoplasmic sperm injection (ICSI) and achieved beneficial outcomes. We hope our research will be helpful in the diagnosis and treatment of male infertility caused by mutation.
PubMed: 35118838
DOI: 10.5534/wjmh.210119 -
Health Science Reports Dec 2021Motility and morphological defects of spermatozoa can cause male infertility. Sperm RNAs are related to sperm quality. They are considered to have clinical values as a...
BACKGROUND AND AIMS
Motility and morphological defects of spermatozoa can cause male infertility. Sperm RNAs are related to sperm quality. They are considered to have clinical values as a biomarker for assessing sperm quality and fertility potential. The annulus, located in the mammalian sperm tail, is required for motility and terminal differentiation of the spermatozoa. SEPT2, 4, 6, 7, and 12 proteins are the main components of the annulus in the sperm tail. The study aimed to evaluate and mRNA contents in the spermatozoa of patients with asthenozoospermia and teratozoospermia.
METHODS
We evaluated transcript levels of and in the sperm samples of 20 asthenozoospermic, 20 teratozoospermic, and 20 normozoospermic samples using quantitative PCR.
RESULTS
The transcript level was significantly decreased in the asthenozoospermia samples compared with the normal group ( = .013). However, was not significantly different between these two groups. The transcript levels of and were not statistically different between teratozoospermic and normozoospermic groups.
CONCLUSION
In conclusion, downregulation of in patients with asthenozoospermia appears to be associated with poor sperm motility.
PubMed: 34849407
DOI: 10.1002/hsr2.436 -
Frontiers in Genetics 2023Primary Ciliary Dyskinesia (PCD) is a rare genetic disorder affecting the function of motile cilia in several organ systems. In PCD, male infertility is caused by...
Primary Ciliary Dyskinesia (PCD) is a rare genetic disorder affecting the function of motile cilia in several organ systems. In PCD, male infertility is caused by defective sperm flagella composition or deficient motile cilia function in the efferent ducts of the male reproductive system. Different PCD-associated genes encoding axonemal components involved in the regulation of ciliary and flagellar beating are also reported to cause infertility due to multiple morphological abnormalities of the sperm flagella (MMAF). Here, we performed genetic testing by next generation sequencing techniques, PCD diagnostics including immunofluorescence-, transmission electron-, and high-speed video microscopy on sperm flagella and andrological work up including semen analyses. We identified ten infertile male individuals with pathogenic variants in (one) and (two) encoding ruler proteins, (two) and (one) encoding radial spoke head proteins, and (two) and (two) encoding CP-associated proteins, respectively. We demonstrate for the first time that pathogenic variants in and cause male infertility due to sperm cell dysmotility and abnormal flagellar RSPH1 and RSPH9 composition. We also provide novel evidence for MMAF in - and -mutant individuals. We show absence or severe reduction of CCDC39 and SPEF2 in sperm flagella of - and -mutant individuals and - and -mutant individuals, respectively. Thereby, we reveal interactions between CCDC39 and CCDC40 as well as HYDIN and SPEF2 in sperm flagella. Our findings demonstrate that immunofluorescence microscopy in sperm cells is a valuable tool to identify flagellar defects related to the axonemal ruler, radial spoke head and the central pair apparatus, thus aiding the diagnosis of male infertility. This is of particular importance to classify the pathogenicity of genetic defects, especially in cases of missense variants of unknown significance, or to interpret variants that are confounded by the presence of the almost identical pseudogene .
PubMed: 36873931
DOI: 10.3389/fgene.2023.1117821