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A new neocentromere locus on chromosome 13 resulting in mosaic tetrasomy for distal 13q and an asymmetric phenotype
Author(s) -
Barwell Julian,
Mazzaschi Roberto,
Bint Sue,
Ogilvie Caroline Mackie,
Elmslie Frances
Publication year - 2004
Publication title -
american journal of medical genetics part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.064
H-Index - 112
eISSN - 1552-4833
pISSN - 1552-4825
DOI - 10.1002/ajmg.a.30208
Subject(s) - genetics , biology , tetrasomy , phenotype , locus (genetics) , chromosome , aneuploidy , gene
An 8‐year‐old girl was referred to the Genetics Centre with mild developmental delay, mild dysmorphic features, and a head circumference on the 98th centile. She was noted to have large irregular ear lobes, torticollis, and mild hemihypertrophy. Karyotype analysis of cultured peripheral lymphocytes and skin fibroblasts revealed the presence of a symmetrical supernumerary marker chromosome in 13% of cells from both tissue types. Further analysis showed that this marker chromosome originated from the distal region of chromosome 13 and contained no centromeric α‐satellite DNA. The marker chromosome was not found in blood from the parents. This case represents a novel symmetrical structure with a previously unreported neocentromere locus, leading to an unusual phenotype. Similar cases of individuals with a chromosome 13 with a neocentromere have been reported. They are reviewed and compared with the current case. The importance of scanning metaphases for abnormalities in individuals presenting with asymmetry is emphasized. © 2004 Wiley‐Liss, Inc.