22q11.2 deletions in a series of patients with non-selective congenital heart defects: incidence, type of defects and parental origin

Abstract

Previous studies have indicated a wide spectrum of incidences of 22q11.2 deletions in isolated and syndromic (sporadic or familial) cases of conotruncal heart defects, whereby the detection rate of the deletion varied from 65% in one study to 0 in another. We analysed 110 patients with non-selective syndromic or isolated non-familial congenital heart malformations by fluorescence in situ hybridization (FISH) using the D22S75 DiGeorge chromosome (DGS) region probe. A 22q11.2 microdeletion has been detected in 9/51 (17.6%) syndromic patients. Five were of maternal origin and four of paternal origin. None of the 59 patients with isolated congenital cardiac defect had a 22q11.2 deletion. We compared the cardiac anomalies of our patients with a 22q11.2 deletion with those of previously published series and we describe types of congenital heart defects which appear to be often associated with a 22q11.2 deletion. The ability to detect such types of heart defects and to provide an early diagnosis of 22q11.2 deletion is particularly relevant in very young infants, who often show only very mild expression of the otherwise well-characterized phenotypes of the DiGeorge/velo-cardio-facial syndrome (DG/VCFS).

Exclusion of chromosomal abnormalities and microdeletions 22q11 and 10p13 in algerian patients with isolated conotruncal malformation

“…Our results confirm the observations brought back by some authors concluding that congenital heart disorders isolated are hardly the consequence of microdeletion 22q11.2 [6,12,28,29] or of microdeletion 10p13-14 [30].…”

“…Microdeletions of chromosomal region 22q11.2 are actually more considered as a principal cause of Di George syndrome [7,8], velocardiofacial syndrome [9] and conotruncal anomaly face syndrome [10,11]. The haploinsufficiency of 22q11 has been found also in some familial cases of heart disease [8,12] and in sporadic patients with isolated CHD [13][14][15][16][17].…”

Ocular pathology in congenital heart disease

“…There are several studies on the prevalence of individual chromosomal abnormalities, like 22q11.2 deletions [31][32][33] (velocardiofacial and DiGeorge syndromes are due to 22q11.2 deletions). Borgmann et al 31 found that routine screening for 22q11.2 deletions in nonsyndromic CHD subjects gave no yield.…”

Congenital heart defects through 30 years

“…Progress in genetic science has disclosed new etiologies for CHD, e.g. microdeletion syndromes [17]. Detection of a CHD should be followed by a thorough clinical and laboratory examination for associated malformations and genetic disorders.…”