Infertility in an adult cohort with primary ciliary dyskinesia: phenotype–gene association

Primary ciliary dyskinesia (PCD) is a rare autosomal recessive disorder (prevalence 1:10 000 to 1:40 000 births) characterised by impaired mucociliary clearance because of abnormal motile ciliary function [1, 2]. Five main ultrastructural PCD phenotypes have been described. Most result from a lack of dynein arms (DAs): no outer and inner DAs (2DAs), outer DAs alone (ODA) or inner DAs with microtubular disorganisation (IDA/MTD); or defects yielding an abnormal central complex (CC). Some patients with genetically confirmed PCD have apparently normal ciliary structure on electron microscopy (nEM). More than 30 genes encoding proteins involved in the structure or assembly of the axoneme, the ciliary internal cytoskeleton, are implicated in PCD [3]; their analysis enables identification of bi-allelic disease-causing mutations in 50–75% of patients. Approximately half of PCD cases are associated with situs inversus , thereby defining Kartagener's syndrome. Moreover, because motile cilia and sperm flagella share common axonemal structures, most PCD-affected males are thought to be infertile [4]. According to the literature, male infertility is caused by severe or total asthenozoospermia and is currently treated by recourse to in vitro fertilisation or intracytoplasmic sperm injection [5, 6]. However, spontaneous fatherhood of PCD patients has been reported. Infertility, observed in 75% of male and 61% of female PCD patients, is dependent on ultrastructural and gene defects We thank all the individuals and their families for their cooperation, as well as all the referring physicians. The researchers participate in the network of COST Action BEAT-PCD (Better Evidence to Advance Therapeutic Options for PCD; no. BM 1407). L. Bassinet, I. Honoré, J.-.F Papon, A. Coste, E. Escudier, S. Amselem, B. Maitre, M. Legendre and S. Christin-Maitre are members of the RadiCONetwork (Inserm, France).