Lin Li1, Xueya Zhou2, Xi Wang3, Jing Wang4, Wei Zhang3, Binbin Wang3, Yunxia Cao5, Kehkooi Kee6. 1. School of Life Sciences, Tsinghua University, Haidian District, Beijing, 100084, China Center for Stem Cell Biology and Regenerative Medicine, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Haidian District, Beijing 100084, China. 2. The Hong Kong Jockey Club Building for Interdisciplinary Research, The University of Hong Kong, 5 Sassoon Road, Pokfulam, Hong Kong. 3. Center for Genetics, National Research Institute for Family Planning, No. 12 Da-Hui-Si Road, Haidian District, Beijing 100081, China Graduate School of Peking Union Medical College, Dongdan three 9, Dongcheng District, Beijing 100730, China. 4. Department of Medical Genetics and Developmental Biology, School of Basic Medical Sciences, Capital Medical University, No. 10 Xitoutiao, Youanmenwai, Fengtai District, Beijing 100069, China. 5. Reproductive Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Meishan Road, Shushan District, Hefei 230022, China Institute of Reproductive Genetics, Anhui Medical University, Meishan Road, Shushan District, Hefei 230022, China Anhui Provincial Engineering Technology Research Center for Biopreservation and Artificial Organs, Meishan Road, Shushan District, Hefei 230022, China kkee@mail.tsinghua.edu.cn caoyunxia_profr@126.com. 6. Center for Stem Cell Biology and Regenerative Medicine, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Haidian District, Beijing 100084, China kkee@mail.tsinghua.edu.cn caoyunxia_profr@126.com.
Abstract
STUDY QUESTION: Does a heterozygous mutation in AMHR2, identified in whole-exome sequencings (WES) of patients with primary ovarian insufficiency (POI), cause a defect in anti-Müllerian hormone (AMH) signaling? SUMMARY ANSWER: The I209N mutation at the adenosine triphosphate binding domain of AMHR2 exerts dominant negative defects in the AMH signaling pathway. WHAT IS KNOWN ALREADY: Previous studies have demonstrated the associations of several sequence variants in AMH or AMHR2 with POI, but no functional assay has been performed to verify whether there was any defect on AMH signaling. STUDY DESIGN, SAMPLES/MATERIALS, METHODS: Ninety-six unrelated female Chinese Han patients were diagnosed with idiopathic POI and subjected to WES. In silico analysis was done for the sequence variants followed by molecular assays to examine the functional effects of the sequence variants in human granulosa cells. In silico analysis, immunostaining, Western analysis, genome-wide expression analysis, quantitatively polymerase chain reaction were applied to the characterization of the sequence variants. MAIN RESULTS AND THE ROLE OF CHANCE: We identified one novel heterozygous missense variant, p.Ala17Glu (A17E), in AMHR2. Subsequently, A17E and two independently reported missense variants, p.Ile209Asn (I209N) and p.Leu354Phe (L354F), were evaluated for effects on the AMH signaling pathway. In silico analysis predicted that all three variants may be deleterious. However, only one variant, I209N, showed severe defects in transducing the AMH signal as well as impaired SMAD1/5/8 phosphorylation. Furthermore, using genome-wide gene expression analysis, we identified genes whose expression was affected by the mutation, these included genes previously reported to participate in AMH signaling as well as newly identified genes. They are EMILIN2, FAM155A, GATA2, HES5, ID1, ID2, RLTPR, SMAD7, CBL, MALAT1 and SMARCA2. LARGE SCALE DATA: None. LIMITATIONS, REASONS FOR CAUTION: Although the in vitro assays demonstrated the causative effect of I209N on AMH signaling, further studies need to validate its long-term effects on folliculogenesis and POI. WIDER IMPLICATIONS OF THE FINDINGS: These results will aid both researchers and clinicians in understanding the molecular pathology of AMH signaling and POI to develop diagnostic assays or therapeutics approaches. STUDY FUNDING AND COMPETING INTERESTS: Research funding is provided by the Ministry of Science and Technology of China [2012CB944704; 2012CB966702], and the National Natural Science Foundation of China [Grant number: 31171429]. The authors declare no conflict of interest.
STUDY QUESTION: Does a heterozygous mutation in AMHR2, identified in whole-exome sequencings (WES) of patients with primary ovarian insufficiency (POI), cause a defect in anti-Müllerian hormone (AMH) signaling? SUMMARY ANSWER: The I209N mutation at the adenosine triphosphate binding domain of AMHR2 exerts dominant negative defects in the AMH signaling pathway. WHAT IS KNOWN ALREADY: Previous studies have demonstrated the associations of several sequence variants in AMH or AMHR2 with POI, but no functional assay has been performed to verify whether there was any defect on AMH signaling. STUDY DESIGN, SAMPLES/MATERIALS, METHODS: Ninety-six unrelated female Chinese Han patients were diagnosed with idiopathic POI and subjected to WES. In silico analysis was done for the sequence variants followed by molecular assays to examine the functional effects of the sequence variants in human granulosa cells. In silico analysis, immunostaining, Western analysis, genome-wide expression analysis, quantitatively polymerase chain reaction were applied to the characterization of the sequence variants. MAIN RESULTS AND THE ROLE OF CHANCE: We identified one novel heterozygous missense variant, p.Ala17Glu (A17E), in AMHR2. Subsequently, A17E and two independently reported missense variants, p.Ile209Asn (I209N) and p.Leu354Phe (L354F), were evaluated for effects on the AMH signaling pathway. In silico analysis predicted that all three variants may be deleterious. However, only one variant, I209N, showed severe defects in transducing the AMH signal as well as impaired SMAD1/5/8 phosphorylation. Furthermore, using genome-wide gene expression analysis, we identified genes whose expression was affected by the mutation, these included genes previously reported to participate in AMH signaling as well as newly identified genes. They are EMILIN2, FAM155A, GATA2, HES5, ID1, ID2, RLTPR, SMAD7, CBL, MALAT1 and SMARCA2. LARGE SCALE DATA: None. LIMITATIONS, REASONS FOR CAUTION: Although the in vitro assays demonstrated the causative effect of I209N on AMH signaling, further studies need to validate its long-term effects on folliculogenesis and POI. WIDER IMPLICATIONS OF THE FINDINGS: These results will aid both researchers and clinicians in understanding the molecular pathology of AMH signaling and POI to develop diagnostic assays or therapeutics approaches. STUDY FUNDING AND COMPETING INTERESTS: Research funding is provided by the Ministry of Science and Technology of China [2012CB944704; 2012CB966702], and the National Natural Science Foundation of China [Grant number: 31171429]. The authors declare no conflict of interest.