title: Azoospermia and trisomy 18p syndrome: a fortuitous association? A patient report and a review of the literature.
abstract: Complete, isolated trisomy of the short arm of chromosome 18 is very rare. To date, only 24 cases of trisomy 18p have been reported in the literature, making it difficult to define a potentially associated phenotype. However, the available evidence suggests that few clinical features are shared by these patients: only variable intellectual disability, variable facial dysmorphism and epilepsy are reported in a few patients. Although three inherited cases of trisomy 18p have already been reported, all were of maternal origin. We report on a patient carrying an isolated complete trisomy 18p translocated to the short arm of chromosome 14 and presenting with facial dysmorphism, mild intellectual disability and non-obstructive azoospermia. Chromosomal abnormalities are more frequent in infertile men with poor sperm quality than the general population. Both numerical and structural chromosomal aberrations have been already reported within the context of azoospermia. To our knowledge, this is the first patient with trisomy 18p to present a fertility impairment due to totally altered spermatogenesis and azoospermia. Although fertility disorders were not mentioned in the four previous reports of men with trisomy 18p, none of the latter had children. We suggest that azoospermia is a previously uncharacterized feature of trisomy 18p syndrome. We further hypothesize that two mechanisms could be responsible of the fertility impairment: a meiotic synapsis defect due to the additional 18p arm that blocks meiosis, and/or overexpression of a gene located on the 18p chromosome involved in the normal testicular development.
authors.affiliation: Médecine et Biologie de la Reproduction, Cytogénétique et CECOS de Picardie, Centre de Biologie Humaine, Centre Hospitalier Universitaire d'Amiens, Rue René Laennec, 80054 Amiens, Cedex 1 France ; UFR de Médecine, Université de Picardie Jules Verne, Amiens, France.
authors.forename: Guillaume
authors.identifier: 0000-0002-5704-6830
authors.initials: G
authors.lastname: Jedraszak
authors.affiliation: Médecine et Biologie de la Reproduction, Cytogénétique et CECOS de Picardie, Centre de Biologie Humaine, Centre Hospitalier Universitaire d'Amiens, Rue René Laennec, 80054 Amiens, Cedex 1 France ; UFR de Médecine, Université de Picardie Jules Verne, Amiens, France.
authors.forename: Henri
authors.initials: H
authors.lastname: Copin
authors.affiliation: Service d'Urologie et Transplantation, Centre Hospitalier Universitaire d'Amiens, Amiens, France.
authors.forename: Manuel
authors.initials: M
authors.lastname: Demailly
authors.affiliation: Médecine et Biologie de la Reproduction, Cytogénétique et CECOS de Picardie, Centre de Biologie Humaine, Centre Hospitalier Universitaire d'Amiens, Rue René Laennec, 80054 Amiens, Cedex 1 France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Quibel
authors.affiliation: Eylau/Unilabs, Paris, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Leclerc
authors.affiliation: Médecine et Biologie de la Reproduction, Cytogénétique et CECOS de Picardie, Centre de Biologie Humaine, Centre Hospitalier Universitaire d'Amiens, Rue René Laennec, 80054 Amiens, Cedex 1 France ; UFR de Médecine, Université de Picardie Jules Verne, Amiens, France.
authors.forename: Marlène
authors.initials: M
authors.lastname: Gallet
authors.affiliation: Médecine et Biologie de la Reproduction, Cytogénétique et CECOS de Picardie, Centre de Biologie Humaine, Centre Hospitalier Universitaire d'Amiens, Rue René Laennec, 80054 Amiens, Cedex 1 France ; UFR de Médecine, Université de Picardie Jules Verne, Amiens, France.
authors.forename: Moncef
authors.initials: M
authors.lastname: Benkhalifa
authors.affiliation: Médecine et Biologie de la Reproduction, Cytogénétique et CECOS de Picardie, Centre de Biologie Humaine, Centre Hospitalier Universitaire d'Amiens, Rue René Laennec, 80054 Amiens, Cedex 1 France.
authors.forename: Aline
authors.initials: A
authors.lastname: Receveur
keywords: Azoospermia; Fertility disorder; Meiotic synapsis defect; Trisomy 18p