The more common form of transposition of the great arteries, dextro-looped TGA, consists of complete inversion of the great vessels, so that the aorta incorrectly arises from the right ventricle and the pulmonary artery incorrectly arises from the ... The more common form of transposition of the great arteries, dextro-looped TGA, consists of complete inversion of the great vessels, so that the aorta incorrectly arises from the right ventricle and the pulmonary artery incorrectly arises from the left ventricle. (In the less common type of TGA, levo-looped TGA, the ventricles are inverted instead) (Goldmuntz et al., 2002). This creates completely separate pulmonary and systemic circulatory systems, an arrangement that is incompatible with life. Patients with TGA often have atrial and/or ventricular septal defects or other types of shunting that allow some mixing between the circulations in order to support life minimally, but surgical intervention is always required. For a discussion of genetic heterogeneity of dextro-looped transposition of the great arteries, see 608808.
Karkera et al. (2007) showed that heterozygous loss-of-function mutations in the GDF1 gene contribute to cardiac defects ranging from tetralogy of Fallot (602880.0003) to transposition of the great arteries (602880.0001) and that decreased TGF-beta (190180) signaling provides a ... Karkera et al. (2007) showed that heterozygous loss-of-function mutations in the GDF1 gene contribute to cardiac defects ranging from tetralogy of Fallot (602880.0003) to transposition of the great arteries (602880.0001) and that decreased TGF-beta (190180) signaling provides a framework for understanding their pathogenesis. These findings implicated perturbations of the TGF-beta signaling pathway in the causation of a major subclass of human congenital heart defects.