Browsing by Author "Lopes, Alexandra M."
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- 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.
- Bi-allelic Mutations in M1AP Are a Frequent Cause of Meiotic Arrest and Severely Impaired Spermatogenesis Leading to Male InfertilityPublication . Wyrwoll, Margot J.; Temel, Şehime G.; Nagirnaja, Liina; Oud, Manon S.; Lopes, Alexandra M.; van der Heijden, Godfried W.; Heald, James S.; Rotte, Nadja; Wistuba, Joachim; Wöste, Marius; Ledig, Susanne; Krenz, Henrike; Smits, Roos M.; Carvalho, Filipa; Gonçalves, João; Fietz, Daniela; Türkgenç, Burcu; Ergören, Mahmut C.; Çetinkaya, Murat; Başar, Murad; Kahraman, Semra; McEleny, Kevin; Xavier, Miguel J.; Turner, Helen; Pilatz, Adrian; Röpke, Albrecht; Dugas, Martin; Kliesch, Sabine; Neuhaus, Nina; Aston, Kenneth I.; Conrad, Donald F.; Veltman, Joris A.; Friedrich, Corinna; Tüttelmann, FrankMale infertility affects ∼7% of men, but its causes remain poorly understood. The most severe form is non-obstructive azoospermia (NOA), which is, in part, caused by an arrest at meiosis. So far, only a few validated disease-associated genes have been reported. To address this gap, we performed whole-exome sequencing in 58 men with unexplained meiotic arrest and identified the same homozygous frameshift variant c.676dup (p.Trp226LeufsTer4) in M1AP, encoding meiosis 1 associated protein, in three unrelated men. This variant most likely results in a truncated protein as shown in vitro by heterologous expression of mutant M1AP. Next, we screened four large cohorts of infertile men and identified three additional individuals carrying homozygous c.676dup and three carrying combinations of this and other likely causal variants in M1AP. Moreover, a homozygous missense variant, c.1166C>T (p.Pro389Leu), segregated with infertility in five men from a consanguineous Turkish family. The common phenotype between all affected men was NOA, but occasionally spermatids and rarely a few spermatozoa in the semen were observed. A similar phenotype has been described for mice with disruption of M1ap. Collectively, these findings demonstrate that mutations in M1AP are a relatively frequent cause of autosomal recessive severe spermatogenic failure and male infertility with strong clinical validity.
- Common Variation in the PIN1 Locus Increases the Genetic Risk to Suffer from Sertoli Cell-Only SyndromePublication . Cerván-Martín, Miriam; Bossini-Castillo, Lara; Guzmán-Jimenez, Andrea; Rivera-Egea, Rocío; Garrido, Nicolás; Luján, Saturnino; Romeu, Gema; Santos-Ribeiro, Samuel; Castilla, José A.; Gonzalvo, M. Carmen; Clavero, Ana; Vicente, F. Javier; Maldonado, Vicente; González-Muñoz, Sara; Rodríguez-Martín, Inmaculada; Burgos, Miguel; Jiménez, Rafael; Pinto, Maria Graça; Pereira, Isabel; Nunes, Joaquim; Sánchez-Curbelo, Josvany; López-Rodrigo, Olga; Pereira-Caetano, Iris; Marques, Patricia Isabel; Carvalho, Filipa; Barros, Alberto; Bassas, Lluís; Seixas, Susana; Gonçalves, João; Larriba, Sara; Lopes, Alexandra M.; Carmona, F. David; Palomino-Morales, Rogelio J.We aimed to analyze the role of the common genetic variants located in the PIN1 locus, a relevant prolyl isomerase required to control the proliferation of spermatogonial stem cells and the integrity of the blood-testis barrier, in the genetic risk of developing male infertility due to a severe spermatogenic failure (SPGF). Genotyping was performed using TaqMan genotyping assays for three PIN1 taggers (rs2287839, rs2233678 and rs62105751). The study cohort included 715 males diagnosed with SPGF and classified as suffering from non-obstructive azoospermia (NOA, n = 505) or severe oligospermia (SO, n = 210), and 1058 controls from the Iberian Peninsula. The allelic frequency differences between cases and controls were analyzed by the means of logistic regression models. A subtype specific genetic association with the subset of NOA patients classified as suffering from the Sertoli cell-only (SCO) syndrome was observed with the minor alleles showing strong risk effects for this subset (ORaddrs2287839 = 1.85 (1.17-2.93), ORaddrs2233678 = 1.62 (1.11-2.36), ORaddrs62105751 = 1.43 (1.06-1.93)). The causal variants were predicted to affect the binding of key transcription factors and to produce an altered PIN1 gene expression and isoform balance. In conclusion, common non-coding single-nucleotide polymorphisms located in PIN1 increase the genetic risk to develop SCO.
- Contribution of TEX15 genetic variants to the risk of developing severe non-obstructive oligozoospermiaPublication . Guzmán-Jiménez, Andrea; González-Muñoz, Sara; Cerván-Martín, Miriam; Rivera-Egea, Rocío; Garrido, Nicolás; Luján, Saturnino; Santos-Ribeiro, Samuel; Castilla, José A.; Gonzalvo, M. Carmen; Clavero, Ana; Vicente, F. Javier; Maldonado, Vicente; Villegas-Salmerón, Javier; Burgos, Miguel; Jiménez, Rafael; Pinto, Maria Graça; Pereira, Isabel; Nunes, Joaquim; Sánchez-Curbelo, Josvany; López-Rodrigo, Olga; Pereira-Caetano, Iris; Marques, Patricia Isabel; Carvalho, Filipa; Barros, Alberto; Bassas, Lluís; Seixas, Susana; Gonçalves, João; Lopes, Alexandra M.; Larriba, Sara; Palomino-Morales, Rogelio J.; Carmona, F. David; Bossini-Castillo, LaraBackground: Severe spermatogenic failure (SPGF) represents one of the most relevant causes of male infertility. This pathological condition can lead to extreme abnormalities in the seminal sperm count, such as severe oligozoospermia (SO) or non-obstructive azoospermia (NOA). Most cases of SPGF have an unknown aetiology, and it is known that this idiopathic form of male infertility represents a complex condition. In this study, we aimed to evaluate whether common genetic variation in TEX15, which encodes a key player in spermatogenesis, is involved in the susceptibility to idiopathic SPGF. Materials and Methods: We designed a genetic association study comprising a total of 727 SPGF cases (including 527 NOA and 200 SO) and 1,058 unaffected men from the Iberian Peninsula. Following a tagging strategy, three tag single-nucleotide polymorphisms (SNPs) of TEX15 (rs1362912, rs323342, and rs323346) were selected for genotyping using TaqMan probes. Case-control association tests were then performed by logistic regression models. In silico analyses were also carried out to shed light into the putative functional implications of the studied variants. Results: A significant increase in TEX15-rs1362912 minor allele frequency (MAF) was observed in the group of SO patients (MAF = 0.0842) compared to either the control cohort (MAF = 0.0468, OR = 1.90, p = 7.47E-03) or the NOA group (MAF = 0.0472, OR = 1.83, p = 1.23E-02). The genotype distribution of the SO population was also different from those of both control (p = 1.14E-02) and NOA groups (p = 4.33–02). The analysis of functional annotations of the human genome suggested that the effect of the SO-associated TEX15 variants is likely exerted by alteration of the binding affinity of crucial transcription factors for spermatogenesis. Conclusion: Our results suggest that common variation in TEX15 is involved in the genetic predisposition to SO, thus supporting the notion of idiopathic SPGF as a complex trait.
- 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.
- Disruption of human meiotic telomere complex genes TERB1, TERB2 and MAJIN in men with non-obstructive azoospermiaPublication . Salas-Huetos, Albert; Tüttelmann, Frank; Wyrwoll, Margot J.; Kliesch, Sabine; Lopes, Alexandra M.; Gonçalves, João; Boyden, Steven E.; Wöste, Marius; Hotaling, James M.; GEMINI Consortium; Nagirnaja, Liina; Conrad, Donald F.; Carrell, Douglas T.; Aston, Kenneth I.Non-obstructive azoospermia (NOA), the lack of spermatozoa in semen due to impaired spermatogenesis affects nearly 1% of men. In about half of cases, an underlying cause for NOA cannot be identified. This study aimed to identify novel variants associated with idiopathic NOA. We identified a nonconsanguineous family in which multiple sons displayed the NOA phenotype. We performed whole-exome sequencing in three affected brothers with NOA, their two unaffected brothers and their father, and identified compound heterozygous frameshift variants (one novel and one extremely rare) in Telomere Repeat Binding Bouquet Formation Protein 2 (TERB2) that segregated perfectly with NOA. TERB2 interacts with TERB1 and Membrane Anchored Junction Protein (MAJIN) to form the tripartite meiotic telomere complex (MTC), which has been shown in mouse models to be necessary for the completion of meiosis and both male and female fertility. Given our novel findings of TERB2 variants in NOA men, along with the integral role of the three MTC proteins in spermatogenesis, we subsequently explored exome sequence data from 1495 NOA men to investigate the role of MTC gene variants in spermatogenic impairment. Remarkably, we identified two NOA patients with likely damaging rare homozygous stop and missense variants in TERB1 and one NOA patient with a rare homozygous missense variant in MAJIN. Available testis histology data from three of the NOA patients indicate germ cell maturation arrest, consistent with mouse phenotypes. These findings suggest that variants in MTC genes may be an important cause of NOA in both consanguineous and outbred populations.
- 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
- Evaluation of Male Fertility-Associated Loci in a European Population of Patients with Severe Spermatogenic ImpairmentPublication . Cerván-Martín, Miriam; Bossini-Castillo, Lara; Rivera-Egea, Rocío; Garrido, Nicolás; Luján, Saturnino; Romeu, Gema; Santos-Ribeiro, Samuel; Castilla, José A.; Gonzalvo, M. Carmen; Clavero, Ana; Vicente, F. Javier; Guzmán-Jiménez, Andrea; Costa, Cláudia; Llinares-Burguet, Inés; Khantham, Chiranan; Burgos, Miguel; Barrionuevo, Francisco J.; Jiménez, Rafael; Sánchez-Curbelo, Josvany; López-Rodrigo, Olga; Peraza, M. Fernanda; Pereira-Caetano, Iris; Marques, Patricia I.; Carvalho, Filipa; Barros, Alberto; Bassas, Lluís; Seixas, Susana; Gonçalves, João; Larriba, Sara; Lopes, Alexandra M.; Palomino-Morales, Rogelio J.; Carmona, F. DavidInfertility is a growing concern in developed societies. Two extreme phenotypes of male infertility are non-obstructive azoospermia (NOA) and severe oligospermia (SO), which are characterized by severe spermatogenic failure (SpF). We designed a genetic association study comprising 725 Iberian infertile men as a consequence of SpF and 1058 unaffected controls to evaluate whether five single-nucleotide polymorphisms (SNPs), previously associated with reduced fertility in Hutterites, are also involved in the genetic susceptibility to idiopathic SpF and specific clinical entities. A significant difference in the allele frequencies of USP8-rs7174015 was observed under the recessive model between the NOA group and both the control group (p = 0.0226, OR = 1.33) and the SO group (p = 0.0048, OR = 1.78). Other genetic associations for EPSTI1-rs12870438 and PSAT1-rs7867029 with SO and between TUSC1-rs10966811 and testicular sperm extraction (TESE) success in the context of NOA were observed. In silico analysis of functional annotations demonstrated cis-eQTL effects of such SNPs likely due to the modification of binding motif sites for relevant transcription factors of the spermatogenic process. The findings reported here shed light on the molecular mechanisms leading to severe phenotypes of idiopathic male infertility, and may help to better understand the contribution of the common genetic variation to the development of these conditions.
- Immune and spermatogenesis-related loci are involved in the development of extreme patterns of male infertilityPublication . Cerván-Martín, Miriam; Tüttelmann, Frank; Lopes, Alexandra M.; Bossini-Castillo, Lara; Rivera-Egea, Rocío; Garrido, Nicolás; Lujan, Saturnino; Romeu, Gema; Santos-Ribeiro, Samuel; Castilla, José A.; Carmen Gonzalvo, M.; Clavero, Ana; Maldonado, Vicente; Vicente, F. Javier; González-Muñoz, Sara; Guzmán-Jiménez, Andrea; Burgos, Miguel; Jiménez, Rafael; Pacheco, Alberto; González, Cristina; Gómez, Susana; Amorós, David; Aguilar, Jesus; Quintana, Fernando; Calhaz-Jorge, Carlos; Aguiar, Ana; Nunes, Joaquim; Sousa, Sandra; Pereira, Isabel; Pinto, Maria Graça; Correia, Sónia; Sánchez-Curbelo, Josvany; López-Rodrigo, Olga; Martín, Javier; Pereira-Caetano, Iris; Marques, Patricia I.; Carvalho, Filipa; Barros, Alberto; Gromoll, Jörg; Bassas, Lluís; Seixas, Susana; Gonçalves, João; Larriba, Sara; Kliesch, Sabine; Palomino-Morales, Rogelio J.; Carmona, F. DavidWe conducted a genome-wide association study in a large population of infertile men due to unexplained spermatogenic failure (SPGF). More than seven million genetic variants were analysed in 1,274 SPGF cases and 1,951 unaffected controls from two independent European cohorts. Two genomic regions were associated with the most severe histological pattern of SPGF, defined by Sertoli cell-only (SCO) phenotype, namely the MHC class II gene HLA-DRB1 (rs1136759, P = 1.32E-08, OR = 1.80) and an upstream locus of VRK1 (rs115054029, P = 4.24E-08, OR = 3.14), which encodes a protein kinase involved in the regulation of spermatogenesis. The SCO-associated rs1136759 allele (G) determines a serine in the position 13 of the HLA-DRβ1 molecule located in the antigen-binding pocket. Overall, our data support the notion of unexplained SPGF as a complex trait influenced by common variation in the genome, with the SCO phenotype likely representing an immune-mediated condition.
- Intronic variation of the SOHLH2 gene confers risk to male reproductive impairmentPublication . Cerván-Martín, Miriam; Suazo-Sánchez, M. Irene; Rivera-Egea, Rocío; Garrido, Nicolás; Luján, Saturnino; Romeu, Gema; Santos-Ribeiro, Samuel; Castilla, José A.; Gonzalvo, M. Carmen; Clavero, Ana; Vicente, F. Javier; Maldonado, Vicente; Burgos, Miguel; Barrionuevo, Francisco J.; Jiménez, Rafael; Sánchez-Curbelo, Josvany; López-Rodrigo, Olga; Peraza, M. Fernanda; Pereira-Caetano, Iris; Marques, Patricia I.; Carvalho, Filipa; Barros, Alberto; Bassas, Lluís; Seixas, Susana; Gonçalves, João; Larriba, Sara; Lopes, Alexandra M.; Palomino-Morales, Rogelio J.; Carmona, F. David; Calhaz-Jorge, Carlos; Aguiar, Ana; Nunes, Joaquim; Sousa, Sandra; Graça Pinto, Maria; Correia, Sónia; Pacheco, Alberto; González, Cristina; Gómez, Susana; Amorós, David; Aguilar, Jesús; Quintana, FernandoObjective: To evaluate whether SOHLH2 intronic variation contributes to the genetic predisposition to male infertility traits, including severe oligospermia (SO) and different nonobstructive azoospermia (NOA) clinical phenotypes. Design: Genetic association study. Setting: Not applicable. Patient(s): Five hundred five cases (455 infertile patients diagnosed with NOA and 50 with SO) and 1,050 healthy controls from Spain and Portugal. Intervention(s): None. Main outcome measure(s): Genomic DNA extraction from peripheral blood mononuclear cells, genotyping of the SOHLH2 polymorphisms rs1328626 and rs6563386 using the TaqMan allelic discrimination technology, case-control association analyses using logistic regression models, and exploration of functional annotations in publicly available databases. Result(s): Evidence of association was observed for both rs6563386 with SO and rs1328626 with unsuccessful sperm retrieval after testicular sperm extraction (TESE-) in the context of NOA. A dominant effect of the minor alleles was suggested in both associations, either when the subset of patients with the manifestation were compared against the control group (rs6563386/SO: P=.021, odds ratio [OR] = 0.51; rs1328626/TESE-: P=.066, OR = 1.46) or against the group of patients without the manifestation (rs6563386/SO: P=.014, OR = 0.46; rs1328626/TESE-: P=.012, OR = 2.43). The haplotype tests suggested a combined effect of both polymorphisms. In silico analyses evidenced that this effect could be due to alteration of the isoform population. Conclusion(s): Our data suggest that intronic variation of SOHLH2 is associated with spermatogenic failure. The genetic effect is likely caused by different haplotypes of rs6563386 and rs1328626, which may predispose to SO or TESE- depending on the specific allelic combination.