A genetic variant in the 3'-UTR of PIWIL4 confers risk for extreme phenotypes of male infertility by altering miR-215 and miR-136 binding affinity.

Study Question: What is the functional impact of the rs508485 genetic polymorphism, located in the 3'-untranslated region (UTR) region of the PIWIL4 gene, on non-obstructive azoospermia (NOA)?

Summary Answer: The rs508485 genetic variant contributes to the pathogenesis of extreme patterns of NOA by modulating PIWIL4 expression through microRNA (miRNA) interactions.

What Is Known Already: Male infertility represents a significant global health challenge with profound societal and economic consequences. One of the most severe forms of male infertility is NOA, which is characterized by severe spermatogenic failure (SPGF) of idiopathic origin in most cases.

Trans-ethnic GWAS meta-analysis of idiopathic spermatogenic failure highlights the immune-mediated nature of Sertoli cell-only syndrome.

Non-obstructive azoospermia, a severe form of male infertility caused by spermatogenic failure (SPGF), has a largely unknown genetic basis across ancestries. To our knowledge, this is the first trans-ethnic meta-analysis of genome-wide association studies on SPGF, involving 2255 men with idiopathic SPGF and 3608 controls from European and Asian populations. Using logistic regression and inverse variance methods, we identify two significant genetic associations with Sertoli cell-only (SCO) syndrome, the most extreme SPGF phenotype.

A comprehensive study of common and rare genetic variants in spermatogenesis-related loci identifies new risk factors for idiopathic severe spermatogenic failure.

Study Question: Can genome-wide genotyping data be analysed using a hypothesis-driven approach to enhance the understanding of the genetic basis of severe spermatogenic failure (SPGF) in male infertility?

Summary Answer: Our findings revealed a significant association between SPGF and the gene and identified three novel genes (, , and ) along with 32 potentially pathogenic rare variants in 30 genes that contribute to this condition.

What Is Known Already: SPGF is a major cause of male infertility, often with an unknown aetiology. SPGF can be due to either multifactorial causes, including both common genetic variants in multiple genes and environmental factors, or highly damaging rare variants.

Comprehensive Evaluation of the Genetic Basis of Keratoconus: New Perspectives for Clinical Translation.

Purpose: Keratoconus (KC) is a corneal disorder with complex etiology, apparently involving both genetic and environmental factors, characterized by progressive thinning and protrusion of the cornea. We aimed to identify novel genetic regions associated with KC susceptibility, elucidate relevant genes for disease development, and explore the translational implications for therapeutic intervention and risk assessment.

Methods: We conducted a genome-wide association study (GWAS) that integrated previously published data with newly generated genotyping data from an independent European cohort.

Changes in environmental exposures over decades may influence the genetic architecture of severe spermatogenic failure.

Study Question: Do the genetic determinants of idiopathic severe spermatogenic failure (SPGF) differ between generations?

Summary Answer: Our data support that the genetic component of idiopathic SPGF is impacted by dynamic changes in environmental exposures over decades.

What Is Known Already: The idiopathic form of SPGF has a multifactorial etiology wherein an interaction between genetic, epigenetic, and environmental factors leads to the disease onset and progression. At the genetic level, genome-wide association studies (GWASs) allow the analysis of millions of genetic variants across the genome in a hypothesis-free manner, as a valuable tool for identifying susceptibility risk loci.

Immune and spermatogenesis-related loci are involved in the development of extreme patterns of male infertility.

We 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.

Common genetic variation in KATNAL1 non-coding regions is involved in the susceptibility to severe phenotypes of male infertility.

Background: Previous studies in animal models evidenced that genetic mutations of KATNAL1, resulting in dysfunction of its encoded protein, lead to male infertility through disruption of microtubule remodelling and premature germ cell exfoliation. Subsequent studies in humans also suggested a possible role of KATNAL1 single-nucleotide polymorphisms in the development of male infertility as a consequence of severe spermatogenic failure.

Objectives: The main objective of the present study is to evaluate the effect of the common genetic variation of KATNAL1 in a large and phenotypically well-characterised cohort of infertile men because of severe spermatogenic failure.

Common Variation in the PIN1 Locus Increases the Genetic Risk to Suffer from Sertoli Cell-Only Syndrome.

We aimed to analyze the role of the common genetic variants located in the 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 taggers (rs2287839, rs2233678 and rs62105751). The study cohort included 715 males diagnosed with SPGF and classified as suffering from non-obstructive azoospermia (NOA, = 505) or severe oligospermia (SO, = 210), and 1058 controls from the Iberian Peninsula.

Effect and in silico characterization of genetic variants associated with severe spermatogenic disorders in a large Iberian cohort.

Background: Severe spermatogenic failure (SpF) represents the most extreme manifestation of male infertility, as it decreases drastically the semen quality leading to either severe oligospermia (SO, <5 million spermatozoa/mL semen) or non-obstructive azoospermia (NOA, complete lack of spermatozoa in the ejaculate without obstructive causes).

Objectives: The main objective of the present study is to analyze in the Iberian population the effect of 6 single-nucleotide polymorphisms (SNPs) previously associated with NOA in Han Chinese through genome-wide association studies (GWAS) and to establish their possible functional relevance in the development of specific SpF patterns.

Materials And Methods: We genotyped 674 Iberian infertile men (including 480 NOA and 194 SO patients) and 1058 matched unaffected controls for the GWAS-associated variants PRMT6-rs12097821, PEX10-rs2477686, CDC42BPA-rs3000811, IL17A-rs13206743, ABLIM1-rs7099208, and SOX5-rs10842262.

Evaluation of Male Fertility-Associated Loci in a European Population of Patients with Severe Spermatogenic Impairment.

Infertility 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.