A missense TGFB2 variant p.(Arg320Cys) causes a paradoxical and striking increase in aortic TGFB1/2 expression

• Published in: European journal of human genetics : EJHG Vol. 25; no. 1; pp. 157 - 160
• Main Authors: Al Maskari, Raya, Yasmin, Cleary, S, Figg, Nikki, Mehta, Sarju, Rassl, Doris, Wilkinson, Ian, O'Shaughnessy, Kevin M
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 01-01-2016
• Subjects: Aneurysms; Aorta; Aortic Aneurysm - genetics; Aortic Aneurysm - pathology; Coronary vessels; Dissection; Evolutionary conservation; Gene Expression Regulation; Genotype & phenotype; Growth factors; Hereditary diseases; Hospitals; Humans; Kinases; Ligands; Loeys-Dietz Syndrome - genetics; Loeys-Dietz Syndrome - pathology; Male; Middle Aged; Mutation; Mutation, Missense; Pathogenesis; Pedigree; Peptides; Phenotypes; Short Report; Transforming Growth Factor beta1 - biosynthesis; Transforming Growth Factor beta1 - genetics; Transforming Growth Factor beta2 - biosynthesis; Transforming Growth Factor beta2 - genetics; Transforming growth factor-b1; Western blotting; United Kingdom > UK; United States > US
• ISSN: 1018-4813; 1476-5438
• DOI: 10.1038/ejhg.2016.143

Loeys-Dietz syndrome (LDS) is an autosomal dominant connective tissue disorder with a range of cardiovascular, skeletal, craniofacial and cutaneous manifestations. LDS type 4 is caused by mutations in TGFβ ligand 2 (TGFB2) and based on the family pedigrees described to date, appears to have a milder clinical phenotype, often presenting with isolated aortic disease. We sought to investigate its molecular basis in a new pedigree. We identified a missense variant p.(Arg320Cys) (NM_003238.3) in a highly evolutionary conserved region of TGFB2 in a new LDS type 4 pedigree with multiple cases of aortic aneurysms and dissections. There was striking upregulation of TGFB1 and TGFB2 expression on immunofluorescent staining, and western blotting of the aortic tissue from the index case confirming the functional importance of the variant. This case highlights the striking paradox of predicted loss-of-function mutations in TGFB2 causing enhanced TGFβ signaling in this emerging familial aortopathy.