P-594 Novel loss of function mutations of follicle-stimulating hormone receptor in a patient with premature ovarian insufficiency identified by infertility gene panel using next generation sequencing: Poster

Sonia Van Dooren, Asma Sassi, Julie Désir, S. Costagliola, Vera Janssens, Mary-Louise Bonduelle, Alexander Gheldof, Dorien Daneels, Anne Delbaere

Research output: Contribution to journalMeeting abstract (Journal)

Abstract

Study question: Can an infertility gene panel (GP) approach uncover genetic etiology of premature ovarian insufficiency (POI) in a patient with primary amenorrhea (PA) and hypergonadotropic hypogonadism? Summary answer: Analysis of GP using next generation sequencing (NGS) identified two new rare inactivating mutations of FSHR which are very likely responsible for the POI phenotype. What is known already: Inactivating mutations of FSHR are an extremely rare cause of POI. Sixteen inactivating mutations of the receptor have been reported so far in POI patients affecting either the extracellular domain (ECD) or the transmembrane domain (TMD) of the FSHR whether in homozygous or compound heterozygous state. In patients with previously characterized FSHR mutations, the phenotype varied depending on the level of inactivation of the receptor. In most cases, patients presented with a primary amenorrhea and streak ovaries. Some mutations were associated with partial or normal breast development, secondary amenorrhea and normal sized ovaries containing preantral and even small antral follicles. Study design, size, duration: Analysis of a panel of 31 genes implicated in POI was performed in a 32 years old Belgian patient presenting an idiopathic POI with PA diagnosed at the age of 17 and normal breast development. This patient consulted our fertility clinic for assisted reproduction with oocyte donation and gave her written informed consent to be tested for a genetic etiology of POI. Participants/materials, setting, methods: We performed GP using NGS @ BRIGHTcore in a patient with POI. FSH and AMH levels were respectively 74UI/L and 1.4ug/L. Karyotype and array CGH were normal. Transvaginal pelvic ultrasound and laparoscopy showed small ovaries with no antral follicles. Transient transfection of COS7 cells was performed with a plasmid containing wild-type FSHR cDNA as well as the two novel FSHR variants identified by GP analysis. Cell surface expression of FSHR variants was tested by FACS. Main results and the role of chance: NGS identified the presence of two new compound heterozygous FSHR missense mutations: c.646 G>A (Gly216Arg) in exon 8 (ECD) and c.1313 C>T (Thr438Ile) in exon 10 (TMD) of the receptor. Both mutations were predicted to be deleterious and/or probably damaging by in silico analysis. The in vitro functional study showed that the expression of both FSHRs variants was barely detectable at the cell surface of transfected COS7 compared to wildtype FSHR. Two experiments showed similar results. Limitations, reasons for caution: Mutations segregation in patient’s family was not evaluated. As FACS experiments used antibodies that recognize an epitope located in the ECD of FSHR, it is possible that the c.646 G>A mutation i414 Abstracts of the 34th Annual Meeting of the ESHRE, Barcelona, Spain 1 to 4 July 2018 alters the epitope recognition by the antibodies without altering the cell surface expression of the receptor. Wider implications of the findings: FSHR mutations are found in less than 1% of POI patients rendering the single gene analysis approach inefficient. We report new FSHR inactivating mutations in a patient presenting PA and hypergonadotropic hypogonadism demonstrating the interesting contribution of a specific GP using NGS to uncover genetic etiologies of idiopathic POI cases. Trial registration number: P2016/196/CCB B406201628264 P-595 Higher resolution aneuploidy screening with targeted
Original languageEnglish
Pages (from-to)i415-415
Number of pages1
JournalHuman Reproduction
Volume33
Issue numberSuppl
Publication statusPublished - 2018
EventESHRE 2018 - CCIB, Barcelona, Spain
Duration: 2 Jul 20184 Jul 2018

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