title: Human Ring Chromosomes - New Insights for their Clinical Significance.
abstract: Twenty-nine as yet unreported ring chromosomes were characterized in detail by cytogenetic and molecular techniques. For FISH (fluorescence in situ hybridization) previously published high resolution approaches such as multicolor banding (MCB), subcentromere-specific multi-color-FISH (cenM-FISH) and two to three-color-FISH applying locus-specific probes were used. Overall, ring chromosome derived from chromosomes 4 (one case), 10 (one case), 13 (five cases), 14, (three cases), 18 (two cases), 21 (eight cases), 22 (three cases), X (five cases) and Y (one case) were studied. Eight cases were detected prenatally, eight due developmental delay and dysmorphic signs, and nine in connection with infertility and/or Turner syndrome. In general, this report together with data from the literature, supports the idea that ring chromosome patients fall into two groups: group one with (severe) clinical signs and symptoms due to the ring chromosome and group two with no obvious clinical problems apart from infertility.
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, D-07743 Jena, Germany ; Department of Morphology and Genetics, Universidade Federal de São Paulo, 04023-900 São Paulo, SP, Brazil.
authors.forename: Rs
authors.initials: R
authors.lastname: Guilherme
authors.forename: E
authors.initials: E
authors.lastname: Klein
authors.forename: Ab
authors.initials: A
authors.lastname: Hamid
authors.forename: S
authors.initials: S
authors.lastname: Bhatt
authors.forename: M
authors.initials: M
authors.lastname: Volleth
authors.forename: A
authors.initials: A
authors.lastname: Polityko
authors.forename: A
authors.initials: A
authors.lastname: Kulpanovich
authors.forename: A
authors.initials: A
authors.lastname: Dufke
authors.forename: B
authors.initials: B
authors.lastname: Albrecht
authors.forename: S
authors.initials: S
authors.lastname: Morlot
authors.forename: L
authors.initials: L
authors.lastname: Brecevic
authors.forename: Mb
authors.initials: M
authors.lastname: Petersen
authors.forename: E
authors.initials: E
authors.lastname: Manolakos
authors.forename: N
authors.initials: N
authors.lastname: Kosyakova
authors.forename: T
authors.initials: T
authors.lastname: Liehr
keywords: Fluorescence  in situ  hybridization (FISH); Genotype-phenotype correlations; Ring chromosomes