RXR alpha deficiency confers genetic susceptibility for aortic sac, conotruncal, atrioventricular cushion, and ventricular muscle defects in mice.

RXR alpha deficiency confers genetic susceptibility for aortic sac, conotruncal, atrioventricular cushion, and ventricular muscle defects in mice.

Retinoid-dependent pathways play a central role in regulating cardiac morphogenesis. Recently, we characterized gene-targeted RXR alpha -/- embryos, which display an atrial-like ventricular phenotype with the development of heart failure and lethality at embryonic day 14.5. To quantitate the frequency and complexity of cardiac morphogenic defects, we now use microdissection and scanning electro...

Molecular and Genetic Insights into Thoracic Aortic Dilation in Conotruncal Heart Defects

Thoracic aortic dilation (AD) has commonly been described in conotruncal defects (CTDs), such as tetralogy of Fallot, double outlet right ventricle and transposition of the great arteries, and truncus arteriosus. Several theories for this have been devised, but fairly recent data indicate that there is likely an underlying histologic abnormality, similar to that seen in Marfan and other connect...

Left ventricular angiocardiography in atrioventricular defects.

The variation in the pathological anatomy of atrioventricular defects influences presentation, prognosis, and the results of surgical treatment. In particular the structure and function of the mitral valve have an important bearing on the success of surgical correction of the deformed valve. The purpose of this paper is to indicate the value of left ventricular angiocardiography in assessing th...

RXR alpha mutant mice establish a genetic basis for vitamin A signaling in heart morphogenesis.

We have established a targeted loss-of-function mutation in the RXR alpha gene in the mouse germ line that results in embryonic lethality between E13.5 and E16.5 when bred to homozygosity. The major defect responsible for lethality is hypoplastic development of the ventricular chambers of the heart, which is manifest as a grossly thinned ventricular wall with concurrent defects in ventricular s...

Endocardial cushion defects.