scholarly journals Sequence analysis of 37 candidate genes for male infertility: challenges in variant assessment and validating genes

Andrology ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 434-441 ◽  
Author(s):  
T. F. Araujo ◽  
C. Friedrich ◽  
C. H. P. Grangeiro ◽  
L. R. Martelli ◽  
J. D. Grzesiuk ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Male Infertility ◽  
Candidate Genes ◽  
Variant Assessment

Creation of knock out and knock in mice by CRISPR/Cas9 to validate candidate genes for human male infertility, interest, difficulties and feasibility

2018 ◽  
Vol 468 ◽  
pp. 70-80 ◽  
Author(s):  
Zine-Eddine Kherraf ◽  
Beatrice Conne ◽  
Amir Amiri-Yekta ◽  
Marie Christou Kent ◽  
Charles Coutton ◽  
...  
Keyword(s):  
Male Infertility ◽  
Candidate Genes ◽  
Knock Out ◽  
Human Male

Deciphering balanced translocations in infertile males by Next Generation Sequencing to identify candidate genes for spermatogenesis disorders

2021 ◽  
Author(s):  
T Yammine ◽  
N Reynaud ◽  
H Lejeune ◽  
F Diguet ◽  
Pa Rollat-Farnier ◽  
...  
Keyword(s):  
Male Infertility ◽  
Candidate Genes ◽  
Gene Disruption ◽  
Chromosomal Rearrangements ◽  
Position Effect ◽  
Copy Number Variations ◽  
Molecular Techniques ◽  
Male Population ◽  
Translocation Breakpoints ◽  
Balanced Translocations

Abstract Male infertility affects about 7% of the general male population. Balanced structural chromosomal rearrangements are observed in 0.4 to 1.4% of infertile males and are considered as a well-established cause of infertility. However, underlying pathophysiological mechanisms still need to be clarified. A strategy combining standard and high throughput cytogenetic and molecular technologies was applied in order to identify the candidate genes that might be implicated in the spermatogenesis defect in three male carriers of different balanced translocations. Fluorescence in situ hybridization (FISH) and whole genome paired-end sequencing were used to characterize translocation breakpoints at the molecular level while exome sequencing was performed in order to exclude the presence of any molecular event independent from the chromosomal rearrangement in the patients. All translocation breakpoints were characterized in the three patients. We identified four variants: a position effect on LACTB2 gene in Patient 1, a heterozygous CTDP1 gene disruption in Patient 2, two single nucleotide variations (SNVs) in DNAH5 gene and a heterozygous 17q12 deletion in Patient 3. The variants identified in this study need further validation to assess their roles in male infertility. This study shows that beside the mechanical effect of structural rearrangement on meiosis, breakpoints could result in additional alterations such as gene disruption or position effect. Moreover, additional SNVs or copy number variations may be fortuitously present and could explain the variable impact of chromosomal rearrangements on spermatogenesis. In conclusion, this study confirms the relevance of combining different cytogenetic and molecular techniques to investigate patients with spermatogenesis disorders and structural rearrangements on genomic scale.

scholarly journals Exome sequencing reveals novel causes as well as new candidate genes for human globozoospermia

2020 ◽  
Vol 35 (1) ◽  
pp. 240-252 ◽  
Author(s):  
M S Oud ◽  
Ö Okutman ◽  
L A J Hendricks ◽  
P F de Vries ◽  
B J Houston ◽  
...  
Keyword(s):  
Male Infertility ◽  
Exome Sequencing ◽  
Candidate Genes ◽  
Sanger Sequencing ◽  
Scientific Research ◽  
National Council ◽  
Pathogenic Variants ◽  
New Genes ◽  
Phenotypic Characterisation ◽  
The Impact

Abstract STUDY QUESTION Can exome sequencing identify new genetic causes of globozoospermia? SUMMARY ANSWER Exome sequencing in 15 cases of unexplained globozoospermia revealed deleterious mutations in seven new genes, of which two have been validated as causing globozoospermia when knocked out in mouse models. WHAT IS KNOWN ALREADY Globozoospermia is a rare form of male infertility characterised by round-headed sperm and malformation of the acrosome. Although pathogenic variants in DPY19L2 and SPATA16 are known causes of globozoospermia and explain up to 70% of all cases, genetic causality remains unexplained in the remaining patients. STUDY DESIGN, SIZE, DURATION After pre-screening 16 men for mutations in known globozoospermia genes DPY19L2 and SPATA16, exome sequencing was performed in 15 males with globozoospermia or acrosomal hypoplasia of unknown aetiology. PARTICIPANTS/MATERIALS, SETTING, METHOD Targeted next-generation sequencing and Sanger sequencing was performed for all 16 patients to screen for single-nucleotide variants and copy number variations in DPY19L2 and SPATA16. After exclusion of one patient with DPY19L2 mutations, we performed exome sequencing for the 15 remaining subjects. We prioritised recessive and X-linked protein-altering variants with an allele frequency of <0.5% in the population database GnomAD in genes with an enhanced expression in the testis. All identified candidate variants were confirmed in patients and, where possible, in family members using Sanger sequencing. Ultrastructural examination of semen from one of the patients allowed for a precise phenotypic characterisation of abnormal spermatozoa. MAIN RESULTS AND ROLE OF CHANCE After prioritisation and validation, we identified possibly causative variants in eight of 15 patients investigated by exome sequencing. The analysis revealed homozygous nonsense mutations in ZPBP and CCDC62 in two unrelated patients, as well as rare missense mutations in C2CD6 (also known as ALS2CR11), CCIN, C7orf61 and DHNA17 and a frameshift mutation in GGN in six other patients. All variants identified through exome sequencing, except for the variants in DNAH17, were located in a region of homozygosity. Familial segregation of the nonsense variant in ZPBP revealed two fertile brothers and the patient’s mother to be heterozygous carriers. Paternal DNA was unavailable. Immunohistochemistry confirmed that ZPBP localises to the acrosome in human spermatozoa. Ultrastructural analysis of spermatozoa in the patient with the C7orf61 mutation revealed a mixture of round heads with no acrosomes (globozoospermia) and ovoid or irregular heads with small acrosomes frequently detached from the sperm head (acrosomal hypoplasia). LIMITATIONS, REASONS FOR CAUTION Stringent filtering criteria were used in the exome data analysis which could result in possible pathogenic variants remaining undetected. Additionally, functional follow-up is needed for several candidate genes to confirm the impact of these mutations on normal spermatogenesis. WIDER IMPLICATIONS OF THE FINDINGS Our study revealed an important role for mutations in ZPBP and CCDC62 in human globozoospermia as well as five new candidate genes. These findings provide a more comprehensive understanding of the genetics of male infertility and bring us closer to a complete molecular diagnosis for globozoospermia patients which would help to predict the success of reproductive treatments. STUDY FUNDING/COMPETING INTEREST(S) This study was funded by The Netherlands Organisation for Scientific Research (918–15-667); National Health and Medical Research Council of Australia (APP1120356) and the National Council for Scientific Research (CONICET), Argentina, PIP grant 11220120100279CO. The authors have nothing to disclose.

Human X chromosome exome sequencing identifies BCORL1 as contributor to spermatogenesis

2020 ◽  
Vol 58 (1) ◽  
pp. 56-65
Author(s):  
Chuncheng Lu ◽  
Yan Zhang ◽  
Yufeng Qin ◽  
Qiaoqiao Xu ◽  
Ran Zhou ◽  
...  
Keyword(s):  
Male Infertility ◽  
Exome Sequencing ◽  
Candidate Genes ◽  
X Chromosome ◽  
Knockout Mice ◽  
Expression Patterns ◽  
Critical Role ◽  
Obstructive Azoospermia ◽  
Independent Population

BackgroundInfertility affects approximately 15% of couples worldwide with male infertility being responsible for approximately 50% of cases. Although accumulating evidence demonstrates the critical role of the X chromosome in spermatogenesis during the last few decades, the expression patterns and potential impact of the X chromosome, together with X linked genes, on male infertility are less well understood.MethodsWe performed X chromosome exome sequencing followed by a two-stage independent population validation in 1333 non-obstructive azoospermia cases and 1141 healthy controls to identify variant classes with high likelihood of pathogenicity. To explore the functions of these candidate genes in spermatogenesis, we first knocked down these candidate genes individually in mouse spermatogonial stem cells (SSCs) using short interfering RNA oligonucleotides and then generated candidate genes knockout mice by CRISPR-Cas9 system.ResultsFour low-frequency variants were identified in four genes (BCORL1, MAP7D3, ARMCX4 and H2BFWT) associated with male infertility. Functional studies of the mouse SSCs revealed that knocking down Bcorl1 or Mtap7d3 could inhibit SSCs self-renewal and knocking down Armcx4 could repress SSCs differentiation in vitro. Using CRISPR-Cas9 system, Bcorl1 and Mtap7d3 knockout mice were generated. Excitingly, Bcorl1 knockout mice were infertile with impaired spermatogenesis. Moreover, Bcorl1 knockout mice exhibited impaired sperm motility and sperm cells displayed abnormal mitochondrial structure.ConclusionOur data indicate that the X-linked genes are associated with male infertility and involved in regulating SSCs, which provides a new insight into the role of X-linked genes in spermatogenesis.

Role of the AZFa candidate genes in male infertility

2000 ◽  
Vol 23 (10) ◽  
pp. 646-651 ◽  
Author(s):  
Carlo Foresta ◽  
E. Moro ◽  
A. Rossi ◽  
M. Rossato ◽  
A. Garolla ◽  
...  
Keyword(s):  
Male Infertility ◽  
Candidate Genes
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