An extra idic(21)(q22.1) in a child with some features of Down’s syndrome
- 1 March 1999
- journal article
- case report
- Published by Wiley in Clinical Genetics
- Vol. 55 (3) , 203-206
- https://doi.org/10.1034/j.1399-0004.1999.550309.x
Abstract
A 30-month-old boy with mental retardation, hypotonia, joint hyperlaxity, Brushfield spots, open mouth, distal axial triradius t", and ulnar loops on both forefingers was found to have a 47,XY, + psu idic(21)(q22.1).ish psu idic(21)(q22.1)(D13Z1/D21Z1 + + ,ETS2-) karyotype. The patient's phenotype, with only some Down's syndrome (DS) features, is probably related to his disomy for most or all of the critical region 21q22.2 q22.3 and agrees with the current notion that certain DS features may also result from 21q proximal duplications. The phenotypical comparison with 2 other patients with a similar extra idic(21) reveals some discrepancies, which may be related to the inherent clinical variability of similar imbalances: yet, a real difference between the tetrasomic segments cannot be excluded. Noticeably, all 3 patients with 21q proximal tetrasomy did not have cardiac defect and exhibited none or just one out of the five other DS phenotypic features attributed to a single gene or cluster on distal 21q22.Keywords
This publication has 11 references indexed in Scilit:
- A large family with subtelomeric translocation t(18;21)(q23;q22.1) and molecular breakpoint in the Down syndrome critical regionHuman Genetics, 1997
- Case Report: Prenatal diagnosis of mosaic tetrasomy 21q confirmed by fluorescence in situ hybridizationClinical Genetics, 1997
- Whither Down syndrome critical regions?Human Genetics, 1997
- An Integrated Map with Cosmid/PAC Contigs of a 4-Mb Down Syndrome Critical RegionGenomics, 1996
- Tetrasomy 21 pter→q22.1 and Down syndrome: Molecular definition of the regionAmerican Journal of Medical Genetics, 1994
- Down syndrome phenotypes: the consequences of chromosomal imbalance.Proceedings of the National Academy of Sciences, 1994
- Mapping of the down syndrome phenotype on chromosome 21 at the molecular levelBiomedicine & Pharmacotherapy, 1994
- Localization of DNA sequences required for human centromere function through an analysis of rearranged Y chromosomesNature Genetics, 1993
- A diagnostic index for Down syndromeThe Journal of Pediatrics, 1982
- Tetrasomy 21 in an infant with down syndrome and congenital leukemiaAmerican Journal of Medical Genetics, 1982