Clinical and molecular characterization of chromosome 7p22.1 microduplication detected by array CGH

Abstract

A 28-month-old Peruvian male presented with speech delay and unusual facial features including prominent forehead, anteverted nares, ocular hypertelorism, and low-set and posteriorly rotated ears with a unilateral preauricular pit. The patient had poor speech with no other developmental delays. Height and weight were normal, although closure of the anterior fontanel and bone age were delayed. Head circumference approximated the 95th centile for age. Following normal routine chromosome analysis and subtelomeric FISH, whole genome microarray revealed a novel interstitial duplication at 7p22.1, approximately 1.7 Mb in size, and containing 13 OMIM annotated genes. FISH studies on the propositus and his parents confirmed that the duplication had occurred de novo. This finding represents the smallest interstitial 7p duplication reported to date, and does not include genes previously implicated as candidates for a 7p duplication syndrome. Common phenotypic features of 7p duplication include distinctive facies with hypertelorism,large anterior fontanel, and intellectual disability. Based on the findings in our patient, and those in previously reported cases of 7p duplication, we propose that genes within this duplicated interval may have a role in skeletal maturation,craniofacial development, and speech acquisition.

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

“…1 (1.7 Mb) who showed all of the common craniofacial features and had cryptorchidism, but did not have global developmental delay or hypotonia. 10 Although the region 7p22.1 contains 27 genes, 13 of which are OMIM-annotated, only one gene (β-actin [ACTB]; OMIM entry *102630; 7p22.1) was commonly observed in both Chui et al 's patient and the patient in the current report. 10 This would mean that ACTB is likely to be the causative factor for features like hypotonia, global developmental delay and cryptorchidism in the current patient.…”

“…10,11 Furthermore, there was an association with ASD. Notably, two reports have associated 7p duplication with this disorder.…”

“…[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.…”

Cardiac malformation of partial trisomy 7p/monosomy 18p and partial trisomy 18p/monosomy 7p in siblings as a result of reciprocal unbalanced malsegregation—and review of the literature

“…Most 7p partial duplication and triplication syndromes result from either malsegregation of a parental translocation or from abnormal recombination caused by parental inversion [4,37]. The moderate clinical characteristics of our female proband may be due to the fact that only small distal parts of Recently, a microduplication of chromosome 7p22.1 has been diagnosed by array CGH in a Peruvian male infant [9]. The interstitial duplication consisted of approximately 1.7 Mb containing 13 OMIM annotated genes.…”

“…Leach et al [26] 46,XY,dup(7)(p11.2p12)mat (2 patients) Chui et al [9] 46, XY,dup(7)(p22.1) We performed a review of literature in order to look for potential hotspots in terms of cardiac malformations on the short arms of chromosomes 7 and 18. Additionally, we asked whether in the context of cardiovascular defects associated with trisomy/monosomy 7p and 18p the general rule applies that duplications are better tolerated than deletions [3].…”