Effect of variants in the FSHR and FSHB genes on the reproductive outcomes of women with endometriosis

• Grant number: 19/16463-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): October 01, 2019
• Effective date (End): September 30, 2020
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Bianca Alves Vieira Bianco
• Grantee: Flávia Altheman Loureiro
• Host Institution: Centro Universitário Saúde ABC. Fundação do ABC. Santo André , SP, Brazil

Abstract

The women fertility depends on the integrity of the hypothalamic-pituitary-gonadal axis. Among the hormones produced from this axis is the follicle stimulating hormone (FSH), a heterodimer composed of a ²-specific chain, encoded by the FSHB gene, associated with an ± chain, and acts by binding to a specific receptor, the FSHR, encoded by the FSHR gene. The ² subunit is responsible for ensuring the specificity of binding to FSHR. In a UK Biobank study, the FSHB:c.-211G>T variant allele was associated with detrimental effects on fertility, but was protective against endometriosis. The FSHR:c.919G>A and FSHR:c.2039G>A variants were previously associated with variability in FSH levels and impact on reproductive outcomes, but the relationship with endometriosis was not elucidated. The objectives of the present study are to evaluate the isolated and combined effects of the variants FSHB:c.-211G>T, FSHR:c.919G>A and FSHR:c.2039G>A on the reproductive outcomes of women with endometriosis. A cross-sectional study will be carried out including 225 norm ovulatory women with a confirmed diagnosis of endometriosis, aged d37 years and who underwent highly complex assisted reproduction treatment (IVF/ICSI). Genotyping will be performed by real-time PCR using the TaqMan system. Clinical data (age, BMI, age of menarche, length of menstrual cycle, type of infertility (primary or secondary), infertility time and antral follicle counting), hormonal profile (TSH, FSH, LH, estradiol, progesterone, prolactin and AMH) and reproductive outcomes (oocytes visualized, oocytes retrieved, MII, number of embryos and pregnancy) will be collected from the medical record. The comparisons between the clinical, hormonal and reproductive variables will be performed according to the three genotypes of each variant and also by the combination of the genotypes according to the MB-MDR method.