Next-generation sequencing and functional evaluation of genetic variants in individuals with DDS 46,XX testicular/ ovotesticular SRY-negative

• Grant number: 21/00684-3
• Support Opportunities: Regular Research Grants
• Duration: July 01, 2021 - June 30, 2023
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Magnus Régios Dias da Silva
• Grantee: Magnus Régios Dias da Silva
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil
• Associated researchers: Marina Malta Letro Kizys Polisel

Abstract

Sex determination in humans is established from the balance of signaling pathways that act in parallel and antagonistically. The pro-testicular pathways pass through the SRY gene's activation, which is a trigger factor for forming the testis. Evidence has suggested the existence of a genetic module for ovarian determination, which is probably composed of more than one factor that acts as SRY in the female's gonadal determination. However, the trigger factors for ovarian development are not yet fully understood. Variations in gonadal development are within the spectrum of Sex Development Disorders / Differences / Diversities (DSD). Among the rare forms of DDS, DDS 46, XX testicular/ovotesticular (DDST / OT) presents testicular tissue in the gonad of individuals 46, XX. The SRY gene's translocation explains part of DDST/OT cases; however, the etiology of SRY-negative cases is not fully understood. In recent years, genetic variants of NR2F2 (nuclear receptor subfamily 2 group F member 2), encoding the transcription factor COUP-TF2 (Chicken Ovalbumin Upstream Promoter Transcription Factor 2), have been described in individuals with DDST/OT SRY-negative. Recently, our research group described for the first time a 3 Mb de novo deletion in locus 15q26.2 in heterozygosis, which contains the NR2F2 gene, in an individual with SRY-negative DDSOT. Reviewing other cases with DDST/OT SRY-negative with undetermined genetic etiology, a new frameshift variant of NR2F2 was identified. In humans, NR2F2 expresses different isoforms (A, B and C) from splicing and alternative transcription initiation sites, but clinical evidence relating this gene to DDS is restricted to the canonical isoform A. Furthermore, despite the well-known expression of COUP-TF2 in adult granulosa and Sertoli cells, the network of genes regulated by COUP-TF2 that orchestrate the gonadal determination is unknown. Based on this rationale, the objectives of this project are to 1) screen for potentially pathogenic allelic variants in individuals with DDST / OT SRY-negative by Whole Exome Sequencing and, in an innovative approach, 2) to identify the signaling pathways regulated by COUP-TF2 in human cell lines of granulosa and Sertoli-like by RNA sequencing, and also 3) to evaluate the effect of new allelic variants of NR2F2 on the transcription activity of COUP-TF2 by a new isoform-specific functional assay. This project aims to expand knowledge about the human sexual determination by elucidating the molecular diagnosis of DDST / OT SRY-negative cases and, thus, advancing the understanding of the role of COUP-TF2 in gonadal development. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SIMONETTI, LUCIANE; FERREIRA, LUCAS G. A.; VIDI, ANGELA CRISTINA; DE SOUZA, JANAINA SENA; KUNII, ILDA S.; MELARAGNO, MARIA ISABEL; DE MELLO, CLAUDIA BERLIM; CARVALHEIRA, GIANNA; DIAS DA SILVA, MAGNUS R.. Intelligence Quotient Variability in Klinefelter Syndrome Is Associated With GTPBP6 Expression Under Regulation of X-Chromosome Inactivation Pattern. FRONTIERS IN GENETICS, v. 12, SEP 20 2021. (17/07053-3, 18/22763-0, 21/00684-3, 18/03511-0)

GUSMAO-SILVA, J., V; LICHTENECKER, D. C. K.; FERREIRA, L. G. A.; GOIS, I; ARGERI, R.; GOMES, G. N.; DIAS-DA-SILVA, M. R.. Body, metabolic and renal changes following cross-sex estrogen/progestogen therapy in a rodent model simulating its use by transwomen. Journal of Endocrinological Investigation, v. N/A, p. 11-pg., 2022-06-11. (21/00684-3)

CORREA-SILVA, SILVIA R. R.; KUNII, ILDA; MITNE-NETO, MIGUEL; MOREIRA, CAROLINE M. M.; DIAS-DA-SILVA, MAGNUS R. R.; ABUCHAM, JULIO. Copy number variation in pituitary stalk interruption syndrome: A large case series of sporadic non-syndromic patients and literature review. Journal of Neuroendocrinology, v. 35, n. 1, p. 11-pg., 2022-12-10. (21/00684-3, 15/26913-8)