title: Unusual small supernumerary marker chromosome (sSMC) 9 in a Klinefelter patient.
abstract: Small supernumerary marker chromosomes (sSMC) are small additional chromosomes characterizable for their origin only by molecular cytogenetic approaches. sSMC have been reported previously in four types of syndromes associated with chromosomal imbalances: in approximately 150 cases with Turner syndrome, 26 cases with Down syndrome and only one case each with Klinefelter syndrome and "Triple-X"-syndrome. Here we report the second case with an sSMC detected in addition to a Klinefelter karyotype. Molecular cytogenetics applying centromere-specific multicolor FISH (cenM-FISH) and a specific subcentromere-specific (subcenM-FISH) probe set characterized the sSMC as a dic(9)(:p12-->q11.1::q11.1--> p11.1:). The reported patient was described with hypogonadism, gynaecomastia plus a bronchial carcinoma. The patient's clinical features are discussed in connection with other Klinefelter cases and possible consequences of presence of the sSMC(9). Furthermore, a suggestion is made for the mode of sSMC-formation in this case.
authors.affiliation: Institut fur Humangenetik und Anthropologie, Jena, Germany. i8lith@mti.uni-jena.de
authors.forename: T
authors.initials: T
authors.lastname: Liehr
authors.forename: K
authors.initials: K
authors.lastname: Mrasek
authors.forename: H
authors.initials: H
authors.lastname: Starke
authors.forename: U
authors.initials: U
authors.lastname: Claussen
authors.forename: G
authors.initials: G
authors.lastname: Schreiber
mesh_terms: D000230:Adenocarcinoma / Q000601:surgery; D000328:Adult; D002874:Chromosome Mapping; D002899:Chromosomes, Human, Pair 9; D020440:Gene Duplication; D005819:Genetic Markers; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D007713:Klinefelter Syndrome / Q000235:genetics*; D008175:Lung Neoplasms / Q000601:surgery; D008297:Male; D009845:Oligospermia / Q000235:genetics
chemical_list: D005819:Genetic Markers