MFAP5 loss-of-function mutations underscore the involvement of matrix alteration in the pathogenesis of familial thoracic aortic aneurysms and dissections

  • Am J Hum Genet. 2014 Dec 4;95(6):736-43. doi: 10.1016/j.ajhg.2014.10.018.
Mathieu Barbier  1 Marie-Sylvie Gross  1 Mélodie Aubart  1 Nadine Hanna  2 Ketty Kessler  1 Dong-Chuan Guo  3 Laurent Tosolini  1 Benoit Ho-Tin-Noe  1 Ellen Regalado  3 Mathilde Varret  1 Marianne Abifadel  1 Olivier Milleron  4 Sylvie Odent  5 Sophie Dupuis-Girod  6 Laurence Faivre  7 Thomas Edouard  8 Yves Dulac  8 Tiffany Busa  9 Laurent Gouya  4 Dianna M Milewicz  3 Guillaume Jondeau  10 Catherine Boileau  11
Affiliations
  • 1. INSERM U1148, Laboratory for Vascular Translational Science, Hôpital Bichat, Université Paris Diderot, Sorbonne Paris Cité, 75018 Paris, France.
  • 2. INSERM U1148, Laboratory for Vascular Translational Science, Hôpital Bichat, Université Paris Diderot, Sorbonne Paris Cité, 75018 Paris, France; AP-HP, Département de Génétique, Hôpital Bichat, 75018 Paris, France.
  • 3. Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
  • 4. AP-HP, Centre de référence pour les syndromes de Marfan et apparentés, Service de Cardiologie, Hôpital Bichat, 75018 Paris, France; UFR de Médecine, Université Paris Diderot, 75018 Paris, France.
  • 5. Service de Génétique Clinique, Hôpital Sud-CHU de Rennes, 35200 Rennes, France.
  • 6. Service de Génétique clinique, Hôpital Louis Pradel, CHU de Lyon-GH Est, 69677 Bron, France.
  • 7. Equipe GAD, EA 4271, Université de Bourgogne, 21000 Dijon, France; Centre de Génétique et Centre de Référence Anomalies du Développement et Syndromes Malformatifs, Hôpital d'Enfants, 21000 Dijon, France.
  • 8. Pédiatrie - Endocrinologie, Génétique et Gynécologie médicale, Hôpital des enfants, CHU de Toulouse, 31059 Toulouse, France.
  • 9. Département de Génétique médicale, Hôpital de la Timone, CHU de Marseille, 13005 Marseille, France.
  • 10. INSERM U1148, Laboratory for Vascular Translational Science, Hôpital Bichat, Université Paris Diderot, Sorbonne Paris Cité, 75018 Paris, France; AP-HP, Centre de référence pour les syndromes de Marfan et apparentés, Service de Cardiologie, Hôpital Bichat, 75018 Paris, France; UFR de Médecine, Université Paris Diderot, 75018 Paris, France.
  • 11. INSERM U1148, Laboratory for Vascular Translational Science, Hôpital Bichat, Université Paris Diderot, Sorbonne Paris Cité, 75018 Paris, France; AP-HP, Département de Génétique, Hôpital Bichat, 75018 Paris, France; AP-HP, Centre de référence pour les syndromes de Marfan et apparentés, Service de Cardiologie, Hôpital Bichat, 75018 Paris, France; UFR de Médecine, Université Paris Diderot, 75018 Paris, France. Electronic address: [email protected].
Abstract

Thoracic Aortic Aneurysm and dissection (TAAD) is an autosomal-dominant disorder with major life-threatening complications. The disease displays great genetic heterogeneity with some forms allelic to Marfan and Loeys-Dietz syndrome, and an important number of cases still remain unexplained at the molecular level. Through whole-exome Sequencing of affected members in a large TAAD-affected family, we identified the c.472C>T (p.Arg158(∗)) nonsense mutation in MFAP5 encoding the extracellular matrix component MAGP-2. This protein interacts with elastin fibers and the microfibrillar network. Mutation screening of 403 additional probands identified an additional missense mutation of MFAP5 (c.62G>T [p.Trp21Leu]) segregating with the disease in a second family. Functional analyses performed on both affected individual's cells and in vitro models showed that these two mutations caused pure or partial haploinsufficiency. Thus, alteration of MAGP-2, a component of microfibrils and elastic fibers, appears as an initiating mechanism of inherited TAAD.