title: Concurrence of ring 21 and trisomy 21 in children of normal parents.
abstract: We present a case of two siblings with different chromosome 21 abnormalities that are both de novo [r(21)/i(21p13) mosaicism and rob(14;21)]. Molecular studies using polymorphic markers have shown that these two aberrations had a common maternal origin. However, the parents were cytogenetically and phenotypically normal. This unusual association has not been reported and is considered to be a unique case that should be addressed.
authors.affiliation: Department of Laboratory Medicine, Chonbuk National University Medical School and Research Institute of Clinical Medicine, Chonbuk National University, 634-18 Keumam-dong, Dukjin-gu, Jeonju 561-712, Korea.
authors.forename: Yong-Gon
authors.initials: YG
authors.lastname: Cho
authors.forename: Tae-Won
authors.initials: TW
authors.lastname: Park
authors.forename: Chang-Seop
authors.initials: CS
authors.lastname: Lee
authors.forename: Sam-Im
authors.initials: SI
authors.lastname: Choi
mesh_terms: D002648:Child; D002869:Chromosome Aberrations; D002891:Chromosomes, Human, Pair 21; D020732:Cytogenetic Analysis; D004314:Down Syndrome; D005260:Female; D017353:Gene Deletion; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics; D007621:Karyotyping; D009030:Mosaicism; D009035:Mothers; D010290:Parents; D035781:Siblings