title: Y chromosome haplogroups: a correlation with testicular dysgenesis syndrome?
abstract: Testicular dysgenesis syndrome encompasses low sperm quality, hypospadias, cryptorchidism and testicular cancer. Epidemiological studies and genetic data from familial cases suggest that testicular dysgenesis syndrome has a common etiology. The Y chromosome is known to encode genes that are involved in germ cell development or maintenance. We have therefore investigated if different classes of Y chromosomes in the general population (Y chromosome haplogroups) are associated with aspects of the testicular dysgenesis syndrome. We defined the Y chromosome haplogroups in individuals from different European counties who presented with either (i) oligo- or azoospermia associated with a Y chromosome microdeletion, (ii) unexplained reduced sperm counts (<20 x 10(6)/ml) or (iii) testicular cancer. We failed to find Y chromosome haplotype associations with either microdeletion formation or testicular cancer. However, in a study of the Danish population, we found that a specific Y chromosome haplogroup (hg26) is significantly overrepresented in men with unexplained reduced sperm counts compared with a Danish control population. The factors encoded by genes on this class of Y chromosome may be particularly susceptible to environmental influences that cause testicular dysgenesis syndrome. Our current data highlight the need for further analyses of clinically well-defined patient groups from a wide range of ethnic and geographic origins.
authors.affiliation: Reproduction, Fertility and Populations, Institut Pasteur, Paris, France. kenmce@pasteur.fr
authors.forename: Ken
authors.initials: K
authors.lastname: McElreavey
authors.forename: Lluis
authors.initials: L
authors.lastname: Quintana-Murci
mesh_terms: D002872:Chromosome Deletion; D041322:Chromosomes, Human, Y / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006059:Gonadal Dysgenesis / Q000235:genetics*; D006061:Gonadal Dysgenesis, 46,XY / Q000235:genetics; D006239:Haplotypes; D006801:Humans; D008297:Male; D009845:Oligospermia / Q000235:genetics; D010375:Pedigree; D013076:Sperm Count; D013577:Syndrome; D013736:Testicular Neoplasms / Q000235:genetics