A report of pure 7p duplication syndrome and review of the literature

Abstract

We report on a case of a 9-month-old female infant with a direct duplication of the 7p13-p22.1 chromosome region diagnosed by combining conventional cytogenetic, FISH, and multicolor banding (MCB) studies. Traditional G-banding detected a partial 7p duplication, which was further demonstrated to be entirely of chromosome 7 origin by using a whole chromosome paint for chromosome 7, and derived from 7p13-p22.1 by MCB. The infant presented with characteristic dysmorphic features, psychomotor retardation, and generalized hypotonia. The phenotypic manifestations of partial 7p trisomy with or without other chromosome involvement are briefly reviewed. Our observations in combination with other cases confirm that 7p trisomy due to dir dup(7p) can be regarded as a defined chromosome syndrome.

Aneuploidy: Cells Losing Their Balance

“…In humans, duplication of a limited number of genes has been found to be associated with disease. For example, duplication of the SNCA gene, which encodes a-synuclein, leads to early onset Alzheimer's disease (reviewed in Farrer 2006); duplication of PMP22 leads to Charcot-Marie-Tooth 1A (CMT1A) neuropathy (reviewed in Hanemann and Muller 1998); and duplication of a fragment of the short arm of chromosome 7 (7p13-p22.1) causes severe developmental abnormalities (Papadopoulou et al 2006).…”

De Novo Duplication of 7p21.1p22.2 in a Child with Autism Spectrum Disorder and Craniofacial Dysmorphism

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] Common features include craniofacial anomalies, a large fontanelle, dysmorphism and psychomotor delay, with hypotonia being the most common complication observed. [1][2][3][4][5][6][7][8]10,11,13 In their review of the literature, Cai et al found that 50% of 7p duplications were the result of balanced reciprocal translocation carriers. 3 Reish et al suggested that these could be an entire duplication duplication.…”

“…1 Chui et al reported a patient with microduplication at 7p22. 1 (1.7 Mb) who showed all of the common craniofacial features and had cryptorchidism, but did not have global developmental delay or hypotonia.…”

Array-Comparative Genomic Hybridization Analysis in Fetuses with Major Congenital Malformations Reveals that 24% of Cases Have Pathogenic Deletions/Duplications

“…The duplication of the short arm of chromosome 7 causes a characteristic pattern of malformations including developmental, craniofacial, skeletal, and cardiovascular anomalies, the severity of which depends on the size of the duplication [Papadopoulou et al, 2006]. The neuronal migration defect could be explained by the deletion of CDON (cell adhesion molecule-related/ downregulated by oncogenes, MIM 608707) and KIRREL3 (Kin of IRRE-like 3, MIM 607761) on chromosome 11, which are 2 genes involved in the control of neuronal migration and axon guidance [Okada et al, 2006;Bhalla et al, 2008].…”