title: Dysregulation of the PDGFRA gene causes inflow tract anomalies including TAPVR: integrating evidence from human genetics and model organisms.
abstract: 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.
authors.affiliation: Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT 84132, USA. steven.bleyl@utah.ed
authors.forename: Steven B
authors.initials: SB
authors.lastname: Bleyl
authors.forename: Yukio
authors.initials: Y
authors.lastname: Saijoh
authors.forename: Noortje A M
authors.initials: NA
authors.lastname: Bax
authors.forename: Adriana C
authors.initials: AC
authors.lastname: Gittenberger-de Groot
authors.forename: Lambertus J
authors.initials: LJ
authors.lastname: Wisse
authors.forename: Susan C
authors.initials: SC
authors.lastname: Chapman
authors.forename: Jennifer
authors.initials: J
authors.lastname: Hunter
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Shiratori
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hamada
authors.forename: Shigehito
authors.initials: S
authors.lastname: Yamada
authors.forename: Kohei
authors.initials: K
authors.lastname: Shiota
authors.forename: Scott E
authors.initials: SE
authors.lastname: Klewer
authors.forename: Mark F
authors.initials: MF
authors.lastname: Leppert
authors.forename: Gary C
authors.initials: GC
authors.lastname: Schoenwolf
mesh_terms: 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
chemical_list: D010982:Platelet-Derived Growth Factor; C075278:platelet-derived growth factor A; D020796:Receptor, Platelet-Derived Growth Factor alpha