Targeted massively parallel sequencing provides comprehensive genetic diagnosis for patients with disorders of sex development

Abstract

Disorders of sex development (DSD) are rare disorders in which there is discordance between chromosomal, gonadal, and phenotypic sex. Only a minority of patients clinically diagnosed with DSD obtains a molecular diagnosis, leaving a large gap in our understanding of the prevalence, management, and outcomes in affected patients. We created a novel DSD-genetic diagnostic tool, in which sex development genes are captured using RNA probes and undergo massively parallel sequencing. In the pilot group of 14 patients, we determined sex chromosome dosage, copy number variation, and gene mutations. In the patients with a known genetic diagnosis (obtained either on a clinical or research basis), this test identified the molecular cause in 100% (7/7) of patients. In patients in whom no molecular diagnosis had been made, this tool identified a genetic diagnosis in two of seven patients. Targeted sequencing of genes representing a specific spectrum of disorders can result in a higher rate of genetic diagnoses than current diagnostic approaches. Our DSD diagnostic tool provides for first time, in a single blood test, a comprehensive genetic diagnosis in patients presenting with a wide range of urogenital anomalies.

Diagnosis of 5α-Reductase 2 Deficiency: Is Measurement of Dihydrotestosterone Essential?

“…Its high capacity may help uncover potentially novel pathophysiological pathways and the interactions of various genetic alterations in modifying phenotypic expression. Application of this technology for the genetic diagnosis of DSD has been published recently (37 ). It is hoped that when more experience on this technology is gathered and when its value in clinical application is thoroughly tested, most, if not all, of the patients with DSD will have a confirmed diagnosis.…”

Genome-wide identification of regulatory elements in Sertoli cells

“…The inability to provide a genetic diagnosis for the majority of individuals with a DSD has led to the development of more robust diagnostic tests to screen large regions of the genome for potential disease-causing mutations, including exome sequencing and copy number variation arrays (White et al, 2011;Arboleda et al, 2013;Baxter et al, 2015). This approach has revealed non-coding mutations upstream of SOX9 that result in DSDs (Kim et al, 2015).…”

“…Finally, we validated the enhancer activity of an active regulatory element located 50 kb upstream of Wt1, which encodes a TF essential for early gonad development. This data will enable future experiments to characterize the regulatory network driving Sertoli cell development and may aid in the identification of non-coding human mutations underlying unexplained cases of DSDs, the majority of which cannot be attributed to mutation within the coding region of a known sexdetermining gene (Arboleda and Vilain, 2011;Arboleda et al, 2013).…”

“…Over 35 other genes have been identified that contribute to DSDs (Arboleda and Vilain, 2011;Arboleda et al, 2013), suggesting that a complex genetic network controls fate commitment in the early gonad. It is evident from human DSD cases where gene dose is altered by duplications or haploinsufficiencies (Foster et al, 1994;Muscatelli et al, 1994;Zanaria et al, 1994;Jordan et al, 2001) that perturbations to the level or timing of individual genes within this network can lead to sex reversals.…”

New Molecular Technologies in Genetic Diagnosis of Male Infertility

“…Новые молекулярно-генетические технологии в диагностике нарушений формирования пола, полового развития и репродукции Наиболее эффективно новые методы анализа ге-нома могут быть использованы в исследовании причин и в диагностике моногенных и гетерогенных генных заболеваний, микроделеционных и микродупликаци-онных синдромов, в том числе с поражением развития или функции репродуктивной системы [20,40,41].…”