title: 19q13.33→qter trisomy in a girl with intellectual impairment and seizures.
abstract: Rearrangements in chromosome 19 are rare. Among the 35 patients with partial 19q trisomy described, only six have a breakpoint defined by array. The 19q duplication results in a variable phenotype, including dysmorphisms, intellectual disability and seizure. In a female patient, although G-banding at 550 band-resolution was normal, multiplex ligation-dependent probe amplification (MLPA) technique and genomic array showed a 10.6 Mb terminal duplication of chromosome 19q13. Fluorescent in situ hybridization (FISH) revealed that the duplicated region was attached to the short arm of chromosome 21 and silver staining showed four small acrocentrics with nucleolar organization region (NOR) activity, suggesting that the breakpoint in chromosome 21 was at p13. This is the first de novo translocation between 19q13.33 and 21p13 described in liveborn. The chromosome 19 is known to be rich in coding and non-coding regions, and chromosomal rearrangements involving this chromosome are very harmful. Furthermore, the 19q13.33→qter region is dense in pseudogenes and microRNAs, which are potent regulators of gene expression. The trisomic level of this region may contribute to deregulation of global gene expression, and consequently, may lead to abnormal development on the carriers of these rearrangements.
authors.affiliation: Universidade Federal de São Paulo - UNIFESP, Department of Morphology and Genetics, São Paulo, Brazil.
authors.forename: Gianna
authors.initials: G
authors.lastname: Carvalheira
authors.affiliation: Universidade Federal de São Paulo - UNIFESP, Department of Morphology and Genetics, São Paulo, Brazil.
authors.forename: Mariana Moysés
authors.initials: MM
authors.lastname: Oliveira
authors.affiliation: Universidade Federal de São Paulo - UNIFESP, Department of Morphology and Genetics, São Paulo, Brazil.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Takeno
authors.affiliation: Universidade Federal de São Paulo - UNIFESP, Department of Mastology, São Paulo, Brazil.
authors.forename: Fernanda Teresa de
authors.initials: FT
authors.lastname: Lima
authors.affiliation: Universidade Federal de São Paulo - UNIFESP, Department of Morphology and Genetics, São Paulo, Brazil.
authors.forename: Vera Ayres
authors.initials: VA
authors.lastname: Meloni
authors.affiliation: Universidade Federal de São Paulo - UNIFESP, Department of Morphology and Genetics, São Paulo, Brazil.
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Melaragno
keywords: Gene regulation; Intellectual impairment; Seizures; Translocation t(19q;21p); de novo 19q13.33 trisomy