title: A jumping Robertsonian translocation: a molecular and cytogenetic study.
abstract: We report a patient with mosaicism for two different Robertsonian translocations, both involving chromosome 21. She carries an unbalanced cell line with an i(21q) and a balanced cell line with a rob(21q22q). She is phenotypically normal but has two children who inherited the i(21q) and have Down syndrome. We demonstrate that both abnormal chromosomes are dicentric and that the proband's 21/21 rearrangement is an isochromosome formed from a maternally derived chromosome 21. We propose a model in which the i(21q) is the progenitor rearrangement in the proband, which subsequently participated in a nonreciprocal rearrangement characteristic of a jumping translocation. In addition, we review other cases of constitutional mosaicism involving jumping translocations.
authors.affiliation: Department of Obstetrics and Gynecology, University of Tennessee, Memphis 38163, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Gross
authors.forename: A T
authors.initials: AT
authors.lastname: Tharapel
authors.forename: O P
authors.initials: OP
authors.lastname: Phillips
authors.forename: L P
authors.initials: LP
authors.lastname: Shulman
authors.forename: E K
authors.initials: EK
authors.lastname: Pivnick
authors.forename: V M
authors.initials: VM
authors.lastname: Park
mesh_terms: D000328:Adult; D002648:Child; D002891:Chromosomes, Human, Pair 21; D002892:Chromosomes, Human, Pair 22; D004314:Down Syndrome / Q000235:genetics; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D007621:Karyotyping; D008297:Male; D009030:Mosaicism; D010375:Pedigree; D014178:Translocation, Genetic