Browsing by Author "Almstrup, Kristian"
Now showing 1 - 5 of 5
Results Per Page
Sort Options
- Actionable secondary findings following exome sequencing of 836 non-obstructive azoospermia cases and their value in patient managementPublication . Kasak, Laura; Lillepea, Kristiina; Nagirnaja, Liina; Aston, Kenneth I.; Schlegel, Peter N.; Gonçalves, João; Carvalho, Filipa; Moreno-Mendoza, Daniel; Almstrup, Kristian; Eisenberg, Michael L.; Jarvi, Keith A.; O’Bryan, Moira K.; Lopes, Alexandra M.; Conrad, Donald F.; Nagirnaja, Liina; Aston, Kenneth I.; Carrell, Douglas T.; Hotaling, James M.; Jenkins, Timothy G.; McLachlan, Rob; O’Bryan, Moira K.; Schlegel, Peter N.; Eisenberg, Michael L.; Sandlow, Jay I.; Jungheim, Emily S.; Omurtag, Kenan R.; Lopes, Alexandra M.; Seixas, Susana; Carvalho, Filipa; Fernandes, Susana; Barros, Alberto; Laan, Maris; Punab, Margus; Rajpert-De Meyts, Ewa; Jørgensen, Niels; Almstrup, Kristian; Krausz, Csilla G.; Jarvi, Keith A.; Punab, Margus; Laan, MarisStudy question: What is the load, distribution and added clinical value of secondary findings (SFs) identified in exome sequencing (ES) of patients with non-obstructive azoospermia (NOA)? Summary answer: One in 28 NOA cases carried an identifiable, medically actionable SF. What is known already: In addition to molecular diagnostics, ES allows assessment of clinically actionable disease-related gene variants that are not connected to the patient's primary diagnosis, but the knowledge of which may allow the prevention, delay or amelioration of late-onset monogenic conditions. Data on SFs in specific clinical patient groups, including reproductive failure, are currently limited. Study design, size, duration: The study group was a retrospective cohort of patients with NOA recruited in 10 clinics across six countries and formed in the framework of the international GEMINI (The GEnetics of Male INfertility Initiative) study. Participants/materials, setting, methods: ES data of 836 patients with NOA were exploited to analyze SFs in 85 genes recommended by the American College of Medical Genetics and Genomics (ACMG), Geisinger's MyCode, and Clinical Genome Resource. The identified 6374 exonic variants were annotated with ANNOVAR and filtered for allele frequency, retaining 1381 rare or novel missense and loss-of-function variants. After automatic assessment of pathogenicity with ClinVar and InterVar, 87 variants were manually curated. The final list of confident disease-causing SFs was communicated to the corresponding GEMINI centers. When patient consent had been given, available family health history and non-andrological medical data were retrospectively assessed. Main results and the role of chance: We found a 3.6% total frequency of SFs, 3.3% from the 59 ACMG SF v2.0 genes. One in 70 patients carried SFs in genes linked to familial cancer syndromes, whereas 1 in 60 cases was predisposed to congenital heart disease or other cardiovascular conditions. Retrospective assessment confirmed clinico-molecular diagnoses in several cases. Notably, 37% (11/30) of patients with SFs carried variants in genes linked to male infertility in mice, suggesting that some SFs may have a co-contributing role in spermatogenic impairment. Further studies are needed to determine whether these observations represent chance findings or the profile of SFs in NOA patients is indeed different from the general population. Limitations, reasons for caution: One limitation of our cohort was the low proportion of non-Caucasian ethnicities (9%). Additionally, as comprehensive clinical data were not available retrospectively for all men with SFs, we were not able to confirm a clinico-molecular diagnosis and assess the penetrance of the specific variants. Wider implications of the findings: For the first time, this study analyzed medically actionable SFs in men with spermatogenic failure. With the evolving process to incorporate ES into routine andrology practice for molecular diagnostic purposes, additional assessment of SFs can inform about future significant health concerns for infertility patients. Timely detection of SFs and respective genetic counseling will broaden options for disease prevention and early treatment, as well as inform choices and opportunities regarding family planning. A notable fraction of SFs was detected in genes implicated in maintaining genome integrity, essential in both mitosis and meiosis. Thus, potential genetic pleiotropy may exist between certain adult-onset monogenic diseases and NOA.
- Assessing the impact of Copy Number Variation on severe spermatogenic impairment with exome dataPublication . Lopes, Alexandra; Nagirnaja, Liina; Filipa, Carvalho; Gonçalves, João; Fernades, Susana; Pereira-Caetano, Iris; Almstrup, Kristian; Rajpert-De Meyts, Ewa; Seixas, Susana; Houston, Brendan; Barros, Alberto; O’Bryan, Moira; Aston, Kenneth; Conrad, Donald; on Behalf of the GEMINI ConsortiumBackground: Azoospermia, the most severe form of male infertility, affects approximately 1% of men worldwide and in the great majority of the cases the etiology of the disease remains unidentified. Given the large number of genes involved in spermatogenesis it is likely that a proportion of cases of idiopathic azoospermia have a genetic basis. We have previously described, using SNP arrays, an excess of low frequency copy number variants (CNVs) in both the autosomes and the sex chromosomes in non-obstructive azoospermia (NOA) suggesting an heterogeneous genetic ethiology for this condition.
- A de novo paradigm for male infertilityPublication . Oud, M.S.; Smits, R.M.; Smith, H.E.; Mastrorosa, F.K.; Holt, G.S.; Houston, B.J.; de Vries, P.F.; Alobaidi, B.K.S.; Batty, L.E.; Ismail, H.; Greenwood, J.; Sheth, H.; Mikulasova, A.; Astuti, G.D.N.; Gilissen, C.; McEleny, K.; Turner, H.; Coxhead, J.; Cockell, S.; Braat, D.D.M.; Fleischer, K.; D’Hauwers, K.W.M.; Schaafsma, E.; Conrad, Donald F.; Nagirnaja, Liina; Aston, Kenneth I.; Carrell, Douglas T.; Hotaling, James M.; Jenkins, Timothy G.; McLachlan, Rob; O’Bryan, Moira K.; Schlegel, Peter N.; Eisenberg, Michael L.; Sandlow, Jay I.; Jungheim, Emily S.; Omurtag, Kenan R.; Lopes, Alexandra M.; Seixas, Susana; Carvalho, Filipa; Fernandes, Susana; Barros, Alberto; Gonçalves, João; Caetano, Iris; Pinto, Graça; Correia, Sónia; Laan, Maris; Punab, Margus; Meyts, Ewa Rajpert-De; Jørgensen, Niels; Almstrup, Kristian; Krausz, Csilla G.; Jarvi, Keith A.; Nagirnaja, L.; Conrad, D.F.; Friedrich, C.; Kliesch, S.; Aston, K.I.; Riera-Escamilla, A.; Krausz, C.; Gonzaga-Jauregui, C.; Santibanez-Koref, M.; Elliott, D. J.; Vissers, L.E.L.M.; Tüttelmann, F.; O’Bryan, M.K.; Ramos, L.; Xavier, M.J.; van der Heijden, G.W.; Veltman, J.A.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.
- Diverse monogenic subforms of human spermatogenic failurePublication . Nagirnaja, Liina; Lopes, Alexandra M.; Charng, Wu-Lin; Miller, Brian; Stakaitis, Rytis; Golubickaite, Ieva; Stendahl, Alexandra; Luan, Tianpengcheng; Friedrich, Corinna; Mahyari, Eisa; Fadial, Eloise; Kasak, Laura; Vigh-Conrad, Katinka; Oud, Manon S.; Xavier, Miguel J.; Cheers, Samuel R.; James, Emma R.; Guo, Jingtao; Jenkins, Timothy G.; Riera-Escamilla, Antoni; Barros, Alberto; Carvalho, Filipa; Fernandes, Susana; Gonçalves, João; Gurnett, Christina A.; Jørgensen, Niels; Jezek, Davor; Jungheim, Emily S.; Kliesch, Sabine; McLachlan, Robert I.; Omurtag, Kenan R.; Pilatz, Adrian; Sandlow, Jay I.; Smith, James; Eisenberg, Michael L.; Hotaling, James M.; Jarvi, Keith A.; Punab, Margus; Rajpert-De Meyts, Ewa; Carrell, Douglas T.; Krausz, Csilla; Laan, Maris; O’Bryan, Moira K.; Schlegel, Peter N.; Tüttelmann, Frank; Veltman, Joris A.; Almstrup, Kristian; Aston, Kenneth I.; Conrad, Donald F.Non-obstructive azoospermia (NOA) is the most severe form of male infertility and typically incurable. Defining the genetic basis of NOA has proven chal lenging, and the most advanced classification of NOA subforms is not based on genetics, but simple description of testis histology. In this study, we exome sequenced over 1000 clinically diagnosed NOA cases and identified a plausible recessive Mendelian cause in 20%. We find further support for 21 genes in a 2-stage burden test with 2072 cases and 11,587 fertile controls. The disrupted genes are primarily on the autosomes, enriched for undescribed human “knockouts”, and, for the most part, have yet to be linked to a Mendelian trait. Integration with single-cell RNA sequencing data shows that azoospermia genes can be grouped into molecular subforms with synchronized expression patterns, and analogs of these subforms exist in mice. This analysis framework identifies groups of genes with known roles in spermatogenesis but also reveals unrecognized subforms, such as a set of genes expressed across mitotic divisions of differentiating spermatogonia. Our findings highlight NOA as an understudied Mendelian disorder and provide a conceptual structure for organizing the complex genetics of male infertility, which may provide a rational basis for disease classification
- Variants in GCNA, X-linked germ-cell genome integrity gene, identified in men with primary spermatogenic failurePublication . Hardy, Jimmaline J.; Wyrwoll, Margot J.; Mcfadden, William; Malcher, Agnieszka; Rotte, Nadja; Pollock, Nijole C.; Munyoki, Sarah; Veroli, Maria V.; Houston, Brendan J.; Xavier, Miguel J.; Kasak, Laura; Punab, Margus; Laan, Maris; Kliesch, Sabine; Schlegel, Peter; Jaffe, Thomas; Hwang, Kathleen; Vukina, Josip; Brieño-Enríquez, Miguel A.; Orwig, Kyle; Yanowitz, Judith; Buszczak, Michael; Veltman, Joris A.; Oud, Manon; Nagirnaja, Liina; Olszewska, Marta; O’Bryan, Moira K.; Conrad, Donald F.; Kurpisz, Maciej; Tüttelmann, Frank; Yatsenko, Alexander N.; Conrad, Donald F.; Nagirnaja, Liina; Aston, Kenneth I.; Carrell, Douglas T.; Hotaling, James M.; Jenkins, Timothy G.; McLachlan, Rob; O’Bryan, Moira K.; Schlegel, Peter N.; Eisenberg, Michael L.; Sandlow, Jay I.; Jungheim, Emily S.; Omurtag, Kenan R.; Lopes, Alexandra M.; Seixas, Susana; Carvalho, Filipa; Fernandes, Susana; Barros, Alberto; Gonçalves, João; Caetano, Iris; Pinto, Graça; Correia, Sónia; Laan, Maris; Punab, Margus; Meyts, Ewa Rajpert-De; Jørgensen, Niels; Almstrup, Kristian; Krausz, Csilla G.; Jarvi, Keith A.; on behalf of GEMINI ConsortiumMale infertility impacts millions of couples yet, the etiology of primary infertility remains largely unknown. A critical element of successful spermatogenesis is maintenance of genome integrity. Here, we present a genomic study of spermatogenic failure (SPGF). Our initial analysis (n=176) did not reveal known gene-candidates but identifed a potentially signifcant single-nucleotide variant (SNV) in X-linked germ-cell nuclear antigen (GCNA). Together with a larger follow-up study (n=2049), 7 likely clinically relevant GCNA variants were identifed. GCNA is critical for genome integrity in male meiosis and knockout models exhibit impaired spermatogenesis and infertility. Single-cell RNA-seq and immunohistochemistry confrm human GCNA expression from spermatogonia to elongated spermatids. Five identifed SNVs were located in key functional regions, including N-terminal SUMO-interacting motif and C-terminal Spartan-like protease domain. Notably, variant p.Ala115ProfsTer7 results in an early frameshift, while Spartan-like domain missense variants p.Ser659Trp and p.Arg664Cys change conserved residues, likely afecting 3D structure. For variants within GCNA’s intrinsically disordered region, we performed computational modeling for consensus motifs. Two SNVs were predicted to impact the structure of these consensus motifs. All identifed variants have an extremely low minor allele frequency in the general population and 6 of 7 were not detected in>5000 biological fathers. Considering evidence from animal models, germ-cell-specifc expression, 3D modeling, and computational predictions for SNVs, we propose that identifed GCNA variants disrupt structure and function of the respective protein domains, ultimately arresting germ-cell division. To our knowledge, this is the frst study implicating GCNA, a key genome integrity factor, in human male infertility.