Exon 47 skipping of fibrillin-1 leads preferentially to cardiovascular defects in patients with thoracic aortic aneurysms and dissections

J Mol Med (Berl). 2013 Jan;91(1):37-47. doi: 10.1007/s00109-012-0931-y. Epub 2012 Jul 8.

Abstract

Excessive activation of the transforming growth factor beta signaling pathway and disorganized cellular skeleton caused by genetic mutations are known to be responsible for the inherited thoracic aortic aneurysms and dissections (TAAD), a life-threatening vascular disease. To investigate the genotype-phenotype correlation, we screened genetic mutations of fibrillin-1 (FBN1), transforming growth factor-β receptor-1 (TGFBR1) and transforming growth factor-β receptor-2 (TGFBR2) for TAAD in 7 affected families and 22 sporadic patients. Of 19 potential mutations identified in FBN1, 11 appeared novel while the others were recurrent. Two mutations were detected in TGFBR2. Eight patients carried no mutation in either of these genes. Characterization of FBN1 c.5917+6T>C in transfected HEK293 cells demonstrated that it caused skipping of exon 47, leading to the loss of the 33th calcium binding epidermal growth factor-like domain associated with Marfan syndrome. Compared with exon 46, skipping of 47 did not cause patients ectopia lentis in all carriers. To correlate genotypes with phenotypes in different human ancestries, we reviewed the published mutational studies on FBN1 and found that the probability of cardiovascular defects were significantly increased in Chinese patients with premature termination codon or splicing mutations than those with missense mutations (91.7 % vs 54.2 %, P = 0.0307) or with noncysteine-involved point mutations than those with cysteine-involved mutations (88.9 % vs 33.3 %, P = 0.0131). Thus, we conclude that exon 47 skipping of FBN1 leads preferentially to cardiovascular defects and human ancestries influence genotype-phenotype correlation in TAAD.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aorta, Thoracic / metabolism*
  • Aorta, Thoracic / pathology
  • Aortic Aneurysm, Thoracic / ethnology
  • Aortic Aneurysm, Thoracic / genetics*
  • Aortic Aneurysm, Thoracic / pathology
  • Aortic Dissection / ethnology
  • Aortic Dissection / genetics*
  • Aortic Dissection / pathology
  • Asian People
  • Child
  • Exons
  • Female
  • Fibrillin-1
  • Fibrillins
  • Gene Expression
  • Genetic Association Studies
  • HEK293 Cells
  • Humans
  • Male
  • Microfilament Proteins / genetics*
  • Middle Aged
  • Mutation
  • Pedigree
  • Protein Serine-Threonine Kinases / genetics
  • Protein Structure, Tertiary
  • Receptor, Transforming Growth Factor-beta Type I
  • Receptor, Transforming Growth Factor-beta Type II
  • Receptors, Transforming Growth Factor beta / genetics
  • Transfection

Substances

  • FBN1 protein, human
  • Fibrillin-1
  • Fibrillins
  • Microfilament Proteins
  • Receptors, Transforming Growth Factor beta
  • Protein Serine-Threonine Kinases
  • Receptor, Transforming Growth Factor-beta Type I
  • Receptor, Transforming Growth Factor-beta Type II
  • TGFBR1 protein, human