title: Segregation of a supernumerary del(15) marker chromosome in sperm.
abstract: Supernumerary marker chromosomes (SMC) can be associated with both normal and abnormal phenotypes. In addition, SMC are found at higher frequency in males with infertility. We identified a SMC, characterized as a del(15)(q11.2) chromosome, in a phenotypically normal male. Using fluorescence in situ hybridization (FISH), we examined the segregation of the del(15) chromosome in sperm from this patient. Only 6.23% of sperm nuclei showed disomy using a chromosome 15 alpha-satellite FISH probe, instead of the expected 50%. In addition, FISH analysis showed no increase for non-disjunction of chromosome 18, excluding an interchromosomal effect for this chromosome. The significant decrease in sperm bearing the del(15) may be due to tissue-specific mosaicism or a result of some form of selection against the del(15) during spermatogenesis. This finding provides a basis for the observation that SMC(15) are less likely to be inherited from a paternal carrier.
authors.affiliation: Division of Medical Genetics, Children's Hospital Oakland, CA 94609, USA. pcotter@itsa.ucsf.edu
authors.forename: P D
authors.initials: PD
authors.lastname: Cotter
authors.forename: E
authors.initials: E
authors.lastname: Ko
authors.forename: S K
authors.initials: SK
authors.lastname: Larabell
authors.forename: A W
authors.initials: AW
authors.lastname: Rademaker
authors.forename: R H
authors.initials: RH
authors.lastname: Martin
mesh_terms: D000328:Adult; D002869:Chromosome Aberrations; D002884:Chromosomes, Human, Pair 15; D020732:Cytogenetic Analysis; D005819:Genetic Markers; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D013094:Spermatozoa / Q000648:ultrastructure*
chemical_list: D005819:Genetic Markers