Phenotypic variation within European carriers of the Y-chromosomal gr/gr deletion is independent of Y-chromosomal background.

BackgroundPrevious studies have compared sperm phenotypes between men with partial [1] deletions within the AZFc region of the Y chromosome with non-carriers, with variable results. Here, we have investigated a separate question, the basis of the variation in sperm phenotype within gr/gr deletion carriers, which ranges from normozoospermia to azoospermia. Differences in the genes removed by independent gr/gr deletions, the occurrence of subsequent duplications or the presence of linked modifying variants elsewhere on the chromosome have been suggested as possible causal factors. We set out to test these possibilities in a large sample of gr/gr deletion carriers with known phenotypes spanning the complete range.ResultsWe assembled a collection of 169 men diagnosed with gr/gr deletions from six centres in Europe and one in Australia, and characterized the DAZ and CDY1 copies retained, the presence or absence of duplications and the Y-chromosomal haplogroup. Although our study had good power to detect factors that accounted for 655.5% of the variation in sperm concentration, no such factor was detected. A negative effect of gr/gr deletions followed by b2/b4 duplication was observed within the normospermic group, which remains to be further explored in a larger study population. Finally, we observed significant geographical differences in the frequency of different subtypes of gr/gr deletions which may have relevance for the interpretation of case control studies dealing with admixed populations.ConclusionsWe conclude that the phenotypic variation of gr/gr carriers in men of European origin is largely independent of the Y-chromosomal background

A de novo paradigm for male infertility

Genetics of Male Infertility Initiative (GEMINI) consortium: Donald F. Conrad, Liina Nagirnaja, Kenneth I. Aston, Douglas T. Carrell, James M. Hotaling, Timothy G. Jenkins, Rob McLachlan, Moira K. O’Bryan, Peter N. Schlegel, Michael L. Eisenberg, Jay I. Sandlow, Emily S. Jungheim, Kenan R. Omurtag, Alexandra M. Lopes, Susana Seixas, Filipa Carvalho, Susana Fernandes, Alberto Barros, João Gonçalves, Iris Caetano, Graça Pinto, Sónia Correia, Maris Laan, Margus Punab, Ewa Rajpert-De Meyts, Niels Jørgensen, Kristian Almstrup, Csilla G. Krausz & Keith A. Jarvi.De novo mutations are known to play a prominent role in sporadic disorders with reduced fitness. We hypothesize that de novo mutations play an important role in severe male infertility and explain a portion of the genetic causes of this understudied disorder. To test this hypothesis, we utilize trio-based exome sequencing in a cohort of 185 infertile males and their unaffected parents. Following a systematic analysis, 29 of 145 rare (MAF < 0.1%) protein-altering de novo mutations are classified as possibly causative of the male infertility phenotype. We observed a significant enrichment of loss-of-function de novo mutations in loss-of-function-intolerant genes (p-value = 1.00 × 10−5) in infertile men compared to controls. Additionally, we detected a significant increase in predicted pathogenic de novo missense mutations affecting missense-intolerant genes (p-value = 5.01 × 10−4) in contrast to predicted benign de novo mutations. One gene we identify, RBM5, is an essential regulator of male germ cell pre-mRNA splicing and has been previously implicated in male infertility in mice. In a follow-up study, 6 rare pathogenic missense mutations affecting this gene are observed in a cohort of 2,506 infertile patients, whilst we find no such mutations in a cohort of 5,784 fertile men (p-value = 0.03). Our results provide evidence for the role of de novo mutations in severe male infertility and point to new candidate genes affecting fertility.This project was funded by The Netherlands Organization for Scientific Research (918-15-667) to J.A.V. as well as an Investigator Award in Science from the Wellcome Trust (209451) to J.A.V. a grant from the Catherine van Tussenbroek Foundation to M.S.O. a grant from MERCK to R.S. a UUKi Rutherford Fund Fellowship awarded to B.J.H. and the German Research Foundation Clinical Research Unit “Male Germ Cells” (DFG, CRU326) to C.F. and F.T. This project was also supported in part by funding from the Australian National Health and Medical Research Council (APP1120356) to M.K.O.B., by grants from the National Institutes of Health of the United States of America (R01HD078641 to D.F.C. and K.I.A., P50HD096723 to D.F.C.) and from the Biotechnology and Biological Sciences Research Council (BB/S008039/1) to D.J.E.info:eu-repo/semantics/publishedVersio

Standards in semen examination:publishing reproducible and reliable data based on high-quality methodology

Biomedical science is rapidly developing in terms of more transparency, openness and reproducibility of scientific publications. This is even more important for all studies that are based on results from basic semen examination. Recently two concordant documents have been published: the 6th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen, and the International Standard ISO 23162:2021. With these tools, we propose that authors should be instructed to follow these laboratory methods in order to publish studies in peer-reviewed journals, preferable by using a checklist as suggested in an Appendix to this article.Peer reviewe

Y-chromosome microdeletions are not associated with SHOX haploinsufficiency

studyquestion: Are Y-chromosome microdeletions associated with SHOX haploinsufficiency, thus representing a risk of skeletal anomalies for the carriers and their male descendents? summary answer: The present study shows that SHOX haploinsufficiency is unlikely to be associated with Y-chromosome microdeletions. what is known already: Y-chromosome microdeletions are not commonly known as a major molecular genetic cause of any pathological condition except spermatogenic failure. However, it has been recently proposed that they are associated not only with infertility but also with anomalies in the pseudoautosomal regions (PAR), among which SHOX haploinsufficiency stands out with a frequency of 5.4% in microdeletion carriers bearing a normal karyotype. This finding implies that sons fathered by men with Y-chromosome defects will not only exhibit fertility problems, but might also suffer from SHOX-related conditions. study design: Five European laboratories (Florence, Mu¨nster, Barcelona, Padova and Ancona), routinely performing Y-chromosome microdeletion screening, were enrolled in a multicenter study. participants/materials, setting, methods: PAR-linked and SHOX copy number variations (CNVs) were analyzed in 224 patients carrying Y-chromosome microdeletions and 112 controls with an intact Y chromosome, using customized X-chromosome-specific array-CGH platforms and/or qPCR assays for SHOX and SRY genes. main results and the role of chance: Our data show that 220 out of 224 (98.2%) microdeletion carriers had a normal SHOX copy number, as did all the controls. No SHOX deletionswere found in any of the examined subjects (patients as well as controls), thus excluding an association with SHOX haploinsufficiency. SHOX duplications were detected in 1.78% of patients (n ¼ 4), of whom two had an abnormal and two a normal karyotype. This might suggest that Y-chromosome microdeletions have a higher incidence forSHOXduplications, irrespective of the patient’s karyotype. However, the only clinical condition observed in our four SHOX-duplicated patients was infertility. limitations, reasons for caution: The number of controls analyzed is rather low to assess whether the SHOX duplications found in the two men with Y-chromosome microdeletions and a normal karyotype represent a neutral polymorphism or are actually associated with the presence of the microdeletion. wider implications of the findings: Men suffering from infertility due to the presence of Y-chromosome microdeletions can resort to artificial reproductive technology (ART) to father their biological children. However, infertile couples must be aware of the risks implied and this makes genetic counseling a crucial step in the patient’s management. This study does not confirm previous alarming data that showed an association between Y-chromosome microdeletions and SHOX haploinsufficiency. Our results imply that deletion carriers have no augmented risk of SHOX-related pathologies (short stature and skeletal anomalies) and indicate that there is no need for radical changes in genetic counseling of Yq microdeletion carriers attempting ART, since the only risk established so far for their male offspring remains impaired spermatogenesis