Dysregulation of the PDGFRA gene causes inflow tract anomalies including TAPVR: integrating evidence from human genetics and model organisms.
Total anomalous pulmonary venous return (TAPVR) is a congenital heart defect inherited via complex genetic and/or environmental factors. We report detailed mapping in extended TAPVR kindreds and mutation analysis in TAPVR patients that implicate the PDGFRA gene in the development of TAPVR. Gene expression studies in mouse and chick embryos for both the Pdgfra receptor and its ligand Pdgf-a show temporal and spatial patterns consistent with a role in pulmonary vein (PV) development. We used an in ovo function blocking assay in chick and a conditional knockout approach in mouse to knock down Pdgfra expression in the developing venous pole during the period of PV formation. We observed that loss of PDGFRA function in both organisms causes TAPVR with low penetrance (approximately 7%) reminiscent of that observed in our human TAPVR kindreds. Intermediate inflow tract anomalies occurred in a higher percentage of embryos (approximately 30%), suggesting that TAPVR occurs at one end of a spectrum of defects. We show that the anomalous pulmonary venous connection seen in chick and mouse is highly similar to TAPVR discovered in an abnormal early stage embryo from the Kyoto human embryo collection. Whereas the embryology of the normal venous pole and PV is becoming understood, little is known about the embryogenesis or molecular pathogenesis of TAPVR. These models of TAPVR provide important insight into the pathogenesis of PV defects. Taken together, these data from human genetics and animal models support a role for PDGF-signaling in normal PV development, and in the pathogenesis of TAPVR.
Bleyl
Steven B
SB
Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT 84132, USA. steven.bleyl@utah.ed
Saijoh
Yukio
Y
Bax
Noortje A M
NA
Gittenberger-de Groot
Adriana C
AC
Wisse
Lambertus J
LJ
Chapman
Susan C
SC
Hunter
Jennifer
J
Shiratori
Hidetaka
H
Hamada
Hiroshi
H
Yamada
Shigehito
S
Shiota
Kohei
K
Klewer
Scott E
SE
Leppert
Mark F
MF
Schoenwolf
Gary C
GC
D000818:Animals; D002642:Chick Embryo; D006330:Heart Defects, Congenital / Q000235:genetics*; D006801:Humans; D051379:Mice; D008817:Mice, Mutant Strains; D023421:Models, Animal; D010982:Platelet-Derived Growth Factor / Q000378:metabolism; D011667:Pulmonary Veins / Q000002:abnormalities*; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics* / Q000378:metabolism
D010982:Platelet-Derived Growth Factor; C075278:platelet-derived growth factor A; D020796:Receptor, Platelet-Derived Growth Factor alpha