The importance of genetic research in cases of severe male factor infertility: A case of 46,XX testicular disorder of sex development.

46,XX testicular disorder of sex development is a rare syndrome characterized by an inconsistency between genotype and phenotype. Affected individuals present variant genitalia between male and ambiguous, non-functional testicles, non-obstructive azoospermia, generally accompanied by hypergonadotropic hypogonadism, a condition known for high levels of gonadotrophic hormones. In some cases, disorders of sexual development are diagnosed during puberty. However, a significant number of individuals show physical characteristics common to males that are not clinically suspicious. As a result, patients with the condition may remain undiagnosed. Many individuals with the condition are diagnosed as adults, due to infertility. The present study discusses the case of an individual who underwent karyotyping for sterility and was found to be a 46,XX male. Despite having a female karyotype, the presence of the sex-determining region Y gene explains the manifestation of masculine secondary sex characteristics. This report highlights the importance of genetic evaluation, considering that carriers may present significant complications resulting from the disorder. Based on correct diagnosis, it is possible to improve a carrier's quality of life through multidisciplinary approaches and help them achieve pregnancy through assisted reproductive technology treatments.

Los ARNs no codificantes largos y su vinculación con las patologías testiculares / Long non-coding RNAs and their involvement in testicular pathologies / RNAs longos não-codificantes e sua ligação com patologias testiculares

Si bien la porción del genoma destinada a la síntesis de proteínas es muy pequeña, actualmente se sabe que casi todo el genoma se expresa bajo forma de ARNs no codificantes. Entre dichos ARNs se encuentran los ARNs no codificantes largos (lncRNAs). Aunque los lncRNAs han sido muy poco estudiados, recientemente han comenzado a centrar la atención de los investigadores, al descubrirse que los mismos pueden desempeñar diversas funciones en la regulación de la expresión génica. Además, su vinculación con patologías ha comenzado a ser puesta de manifiesto. Curiosamente, la cantidad de lncRNAs presentes en el testículo es abrumadoramente mayor que en cualquier otro órgano o tejido estudiado. Los perfiles de expresión de estos lncRNAs varían significativamente a lo largo de la espermatogénesis, y algunas evidencias sugieren que al menos algunos de ellos podrían participar en el proceso de formación de células germinales masculinas. No obstante, el conocimiento sobre el tema es aún muy escaso. En este trabajo revisamos la información disponible sobre la expresión de lncRNAs en el testículo y sus posibles funciones. Asimismo, analizamos algunos ejemplos que ilustran la participación de lncRNAs en el desarrollo de patologías como la infertilidad y el cáncer testicular.

Although the portion of the genome devoted to protein synthesis is very small, it is now known that almost the entire genome is expressed as non-coding RNAs. Among them, there are long noncoding RNAs (lncRNAs). Despite that lncRNAs have been very poorly studied, they have recently started to focus the attention of researchers, as it has been found out that lncRNAs can perform diverse functions in the regulation of gene expression. Besides, their involvement in pathologies is being revealed. Intriguingly, the amount of lncRNAs in the testis is overwhelmingly higher than in any other analyzed organ or tissue. LncRNA expression profiles significantly vary along spermatogenesis, and some evidence suggests that at least some of them could participate in the formation of male germ cells. However, knowledge on the subject is still very scarce. In this work we review the available information on the expression of lncRNAs in testis and their possible roles. We also analyze some examples that illustrate the participation of lncRNAs in the development of pathologies such as infertility and testicular cancer.

Embora a porção do genoma usada para a síntese proteica seja muito pequena, sabe-se agora que quase todo o genoma é expresso na forma de RNAs não-codificantes. Entre esses RNAs estão os longos RNAs não codificantes (lncRNAs). Embora os lncRNAs tenham sido pouco estudados, eles recentemente começaram a focar a atenção dos pesquisadores, ao descobrirem que podem desempenhar diversas funções na regulação da expressão gênica. Além disso, sua ligação com as patologias começou a ser revelada. Curiosamente, a quantidade de lncRNAs presentes nos testículos é esmagadoramente maior do que em qualquer outro órgão ou tecido estudado. Os perfis de expressão destes lncRNAs variam significativamente ao longo da espermatogênese, e algumas evidências sugerem que pelo menos alguns deles poderiam participar no processo de formação de células germinativas masculinas. No entanto, o conhecimento sobre o assunto ainda é muito escasso. Neste trabalho, revisamos as informações disponíveis sobre a expressão de lncRNAs no testículo e suas possíveis funções. Também analisamos alguns exemplos que ilustram a participação dos lncRNAs no desenvolvimento de patologias como infertilidade e câncer testicular.

Genetic and genomic analyses of testicular hypoplasia in Nellore cattle.

Reproductive performance is a key indicator of the long-term sustainability of any livestock production system. Testicular hypoplasia (TH) is a morphological and functional reproductive disorder that affects bulls around the world and consequently causes major economic losses due to reduced fertility rates. Despite the improvements in management practices to enhance performance of affected animals, the use of hypoplastic animals for reproduction might contribute to expand the prevalence of this disorder. The aim of this study was to identify genomic regions that are associated with TH in Nellore cattle by performing a genome-wide association study (GWAS) and functional analyses. Phenotypic and pedigree data from 47,563 animals and genotypes (500,689 Single Nucleotide Polymorphism, SNPs) from 265 sires were used in this study. TH was evaluated as a binary trait measured at 18 months of age. The estimated breeding values (EBVs) were calculated by fitting a single-trait threshold animal model using a Bayesian approach. The SNP effects were estimated using the Bayes C method and de-regressed EBVs for TH as the response variable (pseudo-phenotype). The top-15 ranking windows (5-adjacent SNPs) that explained the highest proportion of variance were identified for further functional and biological network analyses. The posterior mean (95% highest posterior density) of the heritability for TH was 0.16 (0.08; 0.23). The most important genomic windows were located on BTA1, BTA3, BTA4, BTA5, BTA9, BTA22, BTA23, and BTA25. These windows explained together 22.69% of the total additive genetic variance for TH. Strong candidate genes associated with metabolism and synthesis of steroids, cell survival, spermatogenesis process and sperm motility were identified, which might play an important role in the expression of TH. Our findings contribute to a better biological understanding of TH and future characterization of causal variants might enable improved genomic prediction of this trait in beef cattle.

A 46,XX testicular disorder of sex development caused by a Wilms' tumour Factor-1 (WT1) pathogenic variant.

Molecular diagnosis is rarely established in 46,XX testicular (T) disorder of sex development (DSD) individuals with atypical genitalia. The Wilms' tumour factor-1 (WT1) gene is involved in early gonadal development in both sexes. Classically, WT1 deleterious variants are associated with 46,XY disorders of sex development (DSD) because of gonadal dysgenesis. We report a novel frameshift WT1 variant identified in an SRY-negative 46,XX testicular DSD girl born with atypical genitalia. Target massively parallel sequencing involving DSD-related genes identified a novel heterozygous WT1 c.1453_1456del; p.Arg485Glyfs*14 variant located in the fourth zinc finger of the protein which is absent in the population databases. Segregation analysis and microsatellite analysis confirmed the de novo status of the variant that is predicted to be deleterious by in silico tools and to increase WT1 target activation in crystallographic model. This novel and predicted activating frameshift WT1 variant leading to the 46,XX testicular DSD phenotype includes the fourth zinc-finger DNA-binding domain defects in the genetic aetiology of 46,XX DSD.