Browsing by Author "Caetano, Iris"
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- 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.
- Evaluation of the potential association of SOHLH2 polymorphisms with non-obstructive azoospermia susceptibility in a large European populationPublication . Sánchez, Maria I.S.; Martín, Miriam C.; Egea, Rocío R.; Puchalt, Nicolás G.; Marco, Saturnino L.; Magraner, Gema R.; Ribeiro, Samuel; Castilla Alcalá, José A.; Gonzalvo López, Maria C.; Gilabert, Ana C.; Vicente Prados, F. Javier; Ezequiel, Vicente M.; Poyatos, Miguel B.; Rodrigo, Olga L.; Peraza Godoy, María F.; Caetano, Iris; Marques, Patricia; Arnau, Lluis B.; Seixas, Susana; Gonçalves, João; Bartolomé, Sara L.; Lopes, Alexandra; Carmona López, F. David; Palomino Morales, Rogelio J.Non-obstructive azoospermia (NOA) or spermatogenic failure is a complex disease with an important genetic component that causes infertility in men. Known genetic factors associated with NOA include AZF microdeletions of the Y chromosome or karyotype abnormalities; however, most causes of NOA are idiopathic. During the last decade, a large list of associations between single-nucleotide polymorphisms (SNP) and NOA have been reported. However, most of the genetic studies have been performed only in Asian populations. We aimed to evaluate whether the previously described association in Han Chinese between NOA and two SNPs of the SOHLH2 gene (involved in the spermatogenesis process) may also confer risk for NOA in a population of European ancestry. We genotyped a total of 551 NOA patients (218 from Portugal and 333 from Spain) and 1,050 fertile controls (226 from Portugal and 824 from Spain) for the genetic variants rs1328626 and rs6563386 using TaqMan assays. To test for association, we compared the allele and genotype frequencies between cases and controls using an additive model. A haplotype analysis and a meta-analysis using the inverse variance method with our data and those of the original Asian study were also performed. No statistically significant differences were observed in any of the analyses described above. Therefore, considering the high statistical power of our study, it is not likely that the two analysed SOHLH2 genetic variants are related with an increase susceptibility to NOA in the European population.
- Hiperplasia Suprarrenal Congénita - importância da análise molecular no diagnóstico clínico e no aconselhamento genéticoPublication . Gomes, Susana; Caetano, Iris; Silva, Júlia; Gonçalves, JoãoA hiperplasia suprarrenal congénita (CAH) é uma doença autossómica recessiva que ocorre devido a redução, mais ou menos pronunciada, da biossíntese suprarrenal de cortisol. Esta redução pode dever-se a defeitos enzimáticos da esteroidogénese os quais estão também associados a androgénios em excesso. A CAH mais frequente (~ 95% dos casos) deve-se a deficiência em 21-hidroxilase (21-OH, enzima codificada pelo gene CYP21A2), cujas manifestações clínicas, dependendo da gravidade do defeito enzimático, ocorrem predominantemente desde o período neonatal até à adolescência sendo agrupadas na forma clássica e na forma não–clássica da doença. A forma clássica compreende, i) doentes que possuem a ausência completa de atividade em 21-OH resultando na deficiência em cortisol e aldosterona causando a forma de CAH com perda de sal – CAH-PS e, ii) doentes que possuindo uma atividade residual em 21-OH (~1-2%) e mantendo níveis normais de aldosterona, apresentam a forma virilizante simples sem perda de sal – CAH-VS. A forma não-clássica CAH-NC, pode manifestar-se clinicamente desde a infância, corresponde a uma forma menos grave da doença, apresentando um grau variável de sinais de excesso de androgénios, por vezes também pode ser assintomática. Os valores basais de 17-OHP no soro geralmente excedem os 100 ng/mL nas formas clássicas enquanto que nos casos duvidosos e na CAH-NC após o teste de estimulação da ACTH, os níveis de 17-OHP são superiores a 10 ng/mL. A análise molecular do gene CYP21A2 permite confirmar a deficiência em 21-OH e é particularmente relevante na identificação da natureza das alterações patogénicas. Sendo estas classificadas de acordo com a atividade da 21-OH que lhe está associada, permite inferir a gravidade da CAH que lhe corresponde, e assim contribuir para a identificação de casais em risco de terem descendência afetada com a forma clássica da doença, sendo-lhes disponibilizado o aconselhamento genético e o diagnóstico pré-natal. De acordo com os resultados que temos obtido em crianças com CAH da população portuguesa (a apresentar na reunião) as alterações graves mais frequentes (associadas a atividade enzimática da 21-OH residual ou nula), correspondem a codões de terminação prematuros, alterações que afetam o processamento do mRNA e a conversões génicas do CYP21A2. Evidencia-se que um número significativo de casos com CAH-NC possui uma mutação grave num dos alelos pelo que, embora estas crianças/adolescentes quando pretendam procriar, possam ter descendência saudável, dependendo do genótipo do cônjuge, também poderão ter filhos afetados com a forma mais grave da doença. Assim, a análise molecular e aconselhamento genético adequando é essencial para os referidos casais em risco.
- 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.