Screening And Diagnosis Of Male IHH Pathogenic Genes

Objective: Idiopathic Hypogonadotropic Hypogonadism(IHH)refers to the absence of any abnormalities in the structure or function of the hypothalamus-Pituitary-Gonad(HPG),gonadotropins(follicle-stimulating hormone(FSH)and luteinizing hormone(LH))and sex hormones(testosterone(T)and estrogens(E))secretion is impaired,leading to partial or complete loss of pubertal development.Traditionally,congenital IHH can be divided into two forms based on whether the sense of smell is damaged: Kallmann syndrome(KS)and normosmic idiopathic hypogonadotropin hypohypogonadism(n IHH).Based on a comprehensive review of research advances in the genetic etiology,genetic diagnosis,and treatment of IHH disease,we selected 1 KS family,2 n IHH families,and 8 patients with sporadically unrelated IHH to conduct molecular genetics and bioinformatics research.The purpose of this study is to find out the cause of the disease in this patient with KS family,2 n IHH families and 8 patients sporadically unrelated IHH,to help patients with genetic counseling,genetic diagnosis,and clinical treatment,to expand the genotype-phenotype spectrum,and to provide experimental basis for further revealing the pathogenesis of IHH.Methods: The strict sample inclusion method was used in this study.A total of40 male IHH(18 n IHH,22 KS)patients were collected.1)For a case of KS family,we collected peripheral blood of a proband,parents and brother,performed whole exome sequencing(WES)on the proband,then analyzed the sequencing data using bioinformatics,Sanger sequencing validation,explored the amino acid conservation of gene mutation site to determine the cause of disease in patients.2)We collected peripheral blood of the 2 n IHH families,analyzed two probands' WES results,Sanger sequencing and DNAMAN alignment were used to verify the WES results to confirm the pathogenic genes.3)For 8 patients with sporadically unrelated IHH(2 KS and 6n IHH),we collected peripheral blood of the patients,performed WES,then analyzed the possible pathogenic genes of the patients,verified by Sanger sequencing,and further expanded the genotype-phenotype spectrum.Results:(1)SEMA3E missense mutation was found in 1 KS family(c.967C>T,p.P323S).(2)FGFR1 nonsense mutation(c.1981C>T,p.R661X)and KISS1 R known nonsense mutation(c.991C>T,p.R331X)were respectively found in 2 n IHH families.(3)two cases of ANOS1 frameshift mutations(c.844 del C,p.R282fs;c.1886?1887ins CTACTCT,p.L629fs),two cases of FGFR1 frameshift mutations(c.2117?2118ins T,p.E707fs;c.2239?2255del TTCAAGCAGCTGGTGGA,p.F747fs),a case of CHD7 compound heterozygous mutation(c.5695?5698del GGCC,p.G1899 fs and c.5700?5707del ACTTTACT,p.Q1900fs),a case of CHD7 missense mutation(c.5355G>T,p.W1785C),a case of PROKR2 compound heterozygous mutation(c.667T>G,p.Y223 D and c.892C>T,p.R298C)and a case of KISS1 R known homozygous mutation(c.309C>A,p.Y103X)were found in 8 patients with sporadically unrelated IHH.Conclusion: This study identified the virulence gene of 1 KS family,2 n IHH families and 8 patients with sporadically unrelated IHH,which provided effective help for the later treatment and prenatal diagnosis of the patients.Moreover,the genotype-phenotype spectrum of IHH was further expanded,laying an important foundation for further understanding of the function of pathogenic genes related to IHH and subsequent exploration experiments.