Endocardial cushion defect: Further studies of “isolated” versus “syndromic” occurrence

Abstract

The isolated occurrence of endocardial cushion defect (ECD) has been suggested to differ from its occurrence within the context of a syndrome, with regard to the nature (complete or partial) of the defect and the associated cardiovascular malformations. Analysis of data derived from the Baltimore-Washington Infant Study of congenital cardiovascular malformations supports the observation that "syndromic" ECD tends to be of the complete atrioventricular canal type and is less frequently associated with left cardiac anomalies than the isolated form. However, each syndrome has a unique impact on the overall cardiovascular "phenotype", including the ECD. This is especially true for Down and Ivemark syndromes, which are most frequently associated with ECD, but also for other syndromes as well. It is also suggested that isolated ECD is specifically associated with gastrointestinal and urinary tract anomalies. However, in Down syndrome ECD appears to be a specific cardiovascular expression of the trisomic state that is unrelated to other noncardiac malformations. Additional information on the association of ECD with other less common genetic syndromes is needed in order to further investigate the possible genetic basis of this cardiac defect.

Genetic heterogeneity and phenotypic anomalies in children with atrioventricular canal defect and tetralogy of Fallot

“…Excluding cases with DS, the AVCD is also frequently associated with other genetic syndromes and extracardiac anomalies (Marino et al, 1990;Carmi et al, 1992;Digilio et al, 1999;Pierpont et al, 2000). We found that 87.5% of our patients with AVCD and TOF had a genetic syndrome or extracardiac anomalies.…”

A recognisable behavioural phenotype associated with terminal deletions of the short arm of chromosome 8

“…Interestingly, in one of the patients presented here, the AVSD was associated with heterotaxy, including isomerism of the atria and azygos continuation as well as malrotation of the gut. This constellation of malformations is also seen in the polyasplenia syndrome, another disorder frequently associated with AVSD [Carmi et al, 1992]. It is, therefore, possible that the heart malformations seen in chromosome 8p deletions are related to a laterality defect, which can sometimes manifest only at the level of the heart [Devriendt et al, 1994].…”

Atrioventricular canal and 3C (cranio‐cerebello‐cardiac) syndrome

“…This is the case of AVC found in Down syndrome [Marino, 19931 and deletion 8p patients [Marino et al, 1992;Digilio et al, 19931. AVC is occasionally observed also in children with other aneuploidies, including trisomy 18, trisomy 9, deletion lop and monosomy X [Carmi et al, 1992;Marino et al, 1989;1991a;Digilio et al, 19911. In addition, AVC may be a component of some mendelian disorders including Holt-Oram, Smith-Lemli-Opitz, DiGeorge syndromes, and mainly Ellis-van Creveld syndrome [Carmi et al, 1992;Marino et al, 1991b;Lynch et al, 19681.…”