title: Mosaic rearrangement of chromosome 18: characterization by FISH mapping and DNA studies shows trisomy 18p and monosomy 18p both of paternal origin.
abstract: Structural abnormalities of chromosome 18p mainly consist of isochromosomes of the short arm, which result in tetrasomy 18p. Trisomy 18p is much rarer, and less well characterized. We report on a 12-year-old girl with minor facial anomalies, delayed development, abnormal hands, atopic dermatitis, and hearing loss. She was mosaic for two abnormal cell lines in peripheral blood. In 90% of cells, a dicentric chromosome with duplication of the whole short arm of chromosome 18 resulted in trisomy 18p; 10% of cells had monosomy 18p, arising from a t(14;18)(p11;q11). FISH mapping, with multiple region specific and locus specific probes from the short and long arm of chromosome 18, showed that the structure of the dicentric chromosome 18 was 18pter-->18q23::18q11-->18pter. DNA polymorphisms for chromosome 18 showed that the abnormalities of chromosome 18 were paternal in origin. Combining all results, we could link the trisomy 18p and monosomy 18p to a common origin via a complex series of events in an early mitosis.
authors.affiliation: Cytogenetics Department, Royal Alexandra Hospital for Children, Westmead, Australia.
authors.forename: G
authors.initials: G
authors.lastname: Oner
authors.forename: A
authors.initials: A
authors.lastname: Jauch
authors.forename: T
authors.initials: T
authors.lastname: Eggermann
authors.forename: R
authors.initials: R
authors.lastname: Hardwick
authors.forename: S
authors.initials: S
authors.lastname: Kirsch
authors.forename: K
authors.initials: K
authors.lastname: Schiebel
authors.forename: G
authors.initials: G
authors.lastname: Rappold
authors.forename: L
authors.initials: L
authors.lastname: Robson
authors.forename: A
authors.initials: A
authors.lastname: Smith
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics; D000328:Adult; D002648:Child; D002869:Chromosome Aberrations; D002883:Chromosomes, Human, Pair 14 / Q000235:genetics; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D004247:DNA / Q000235:genetics; D003638:Deafness; D003876:Dermatitis, Atopic; D005192:Family Health; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D009006:Monosomy; D009030:Mosaicism; D013064:Speech Disorders; D014178:Translocation, Genetic; D014314:Trisomy
chemical_list: D004247:DNA