Identification Of Pathogenic Genes For The Reduced Generation Of Multiple Motile Cilia In Human Reproductive Tract Epithelium And Research On Assisted Reproduction Therapy

Objective: PCD（Primary ciliary dyskinesia）is an autosomal recessive genetic disorder,and the related gene mutations cause structural abnormalities or dysfunction of cilia.RGMC（Reduced generation of multiple motile cilia）is a special type of PCD characterized by multiciliogenesis disorder.RGMC-patients have difficulty clearing mucus from the respiratory tract and abnormal gamete transport in the efferent ducts（EDs）/oviducts.This study identified novel RGMC pathogenic mutations,elucidated the genetic etiology,and explored the efficacy of IVF/ICSI in RGMC patients.Methods: This study recruited 10（seven males and three females）primary infertility patients in the Reproductive Center of the First Affiliated Hospital of Anhui Medical University.In our PCD cohort,9 of the 10 patients were from a consanguineous family;all patients with idiopathic and primary infertility presented to the reproductive center.Importantly,these 10 patients suffered from chronic airway infection.Acquired respiratory and reproductive tract diseases were ruled out in all patients by family genetic analysis,systematic history collection and clinical examination.WES was performed in peripheral blood and clinical examination results confirmed PCD.H＆E staining and SEM were used to observe the cilia distribution of reproductive tract epithelium,TEM was used to explore the changes of basal body number,and IF staining was used to analyze the changes of expression of corresponding protein.Results: Homozygous frameshift mutations in MCIDAS（c.186 dup T,p.Pro63Serfs*22）and CCNO（c.262＿263ins GGCCC,p.Gln88Argfs*8）were identified in one male and one female participant from two unrelated consanguineous families by WES and Sanger sequencing.H＆E staining/SEM revealed abnormal MCCs in the mutated EDs/oviducts.Furthermore,TEM revealed significantly reduced BBs.IF staining showed the absence of MCIDAS and CCNO signals in the affected tissues and confirmed that MCIDAS acts upstream of CCNO in the context of multiciliogenesis in the reproductive tract epithelium.IVF/ICSI was successful,with a positive pregnancy outcome in RGMC patients.Conclusion: MCIDAS acts upstream of CCNO in the context of multiciliogenesis in the reproductive tract epithelium.MCIDAS and CCNO homozygous loss of function mutations resulted in impaired DD pathway.The reduced number of amplified centrioles causes RGMC in the mutated EDs/oviducts.RGMC-related infertility can be achieved through clinical pregnancy using IVF/ICSI techniques.