Successful in vitro maturation of oocytes in a woman with gonadotropin-resistant ovary syndrome associated with a novel combination of FSH receptor gene variants: a case report

International audienceInfertility due to Gonadotropin-Resistant Ovary Syndrome (GROS) is a rare type of hypergonadotropic hypogonadism. Here, we report an original case of GROS, associated with compound heterozygous follicle-stimulating hormone receptor (FSHR) variants, in a woman who achieved a live birth by in vitro maturation (IVM) of her oocytes. This 31-year-old woman consulted our assisted reproduction center for a second opinion after having been advised, because of pervasive high serum follicle-stimulating hormone (FSH) levels, to pursue in vitro fertilization (IVF) with donor oocytes. She presented with primary infertility and progressively prolonged menstrual cycles. Her serum FSH levels were indeed found to be high, but in discordance with a normal anti-Müllerian hormone (AMH) level and antral follicle count. Genetic investigation found the patient to be compound heterozygous for two FSHR variants: I160T, a known pathologic variant, and N558H, which has never been previously reported. As there was no ovarian response to high daily doses of exogenous gonadotropins, IVM was proposed to the patient with success and she finally delivered at term a healthy boy. Effects of the receptor variants were analyzed in heterologous cells. Whereas the I160T mutation blocked FSHR membrane trafficking and FSH-stimulated cAMP-dependent signaling in transfected CHO cells, the novel variant, N558H, functioned equivalently to wild-type FSHR in the assays employed. In conclusion, IVM should always be offered as a first-line therapy to infertile women presenting with GROS. The N558H variant discovered in FSHR is novel, but its functional significance, if any, is unresolved and merits further investigation as it may be associated with a recessive FSHR-related disorder