SEARCH RESULTS FOR: Marfan-Syndrome

Marfan-Syndrome

Marfan Syndrome: Pathogenesis and Clinical Findings Inherited or acquired mutation in TGFBR1/2 gene (TGF-β receptor) Dural ectasia (widening of the dural sac) Diminished and disorganized dural elastic fibres Abnormalities in connective tissues Tear in the aortic intima (innermost layer of aorta) Aortic dissection Type A (tear in ascending aorta) > Type B (tear in descending aorta) Back pain Sensory and motor deficits Ectopia lentis (lens dislocation) Development of lung bullae and blebs Rupture of bullae/blebs Pneumothorax ** Abnormal properties of lens + cornea ** Scoliosis ** Myopia Tall stature Chest wall (pectus) Inherited (autosomal dominant) or de novo mutation in FBN1 gene Distortion of neural roots Thinning of ciliary zonules of the eye Weakness and rupture of alveolar tissue Production of aberrant or reduced fibrillin-1 Formation of unstable microfibrils in extracellular matrix of connective tissues ** inactivate TGF-β1 ↑ production of matrix metalloproteinases ↑ cellular signaling cascades ↑ production of growth factors in the endocardium Cell proliferation and apoptosis suppression in mitral valve leaflets Change in valvular architecture Mitral prolapse Mitral regurgitation ↑ degradation of extracellular matrix Thinning of the aortic media Weakness of the aortic wall Inability of fibrillin- 1 to sequester and ↑ TGF-β1 signalling Abbreviations • TGF-β: Transforming growth factor beta (a cytokine) Notes **The underlying mechanisms are unclear Authors: Tony Gu Reviewers: Amanda Nguyen Davis Maclean Yan Yu* Michelle Keir* * MD at time of publication Aortic root dilation Aortic valve leaflets stretched outwards, unable to fully close Aortic regurgitation Aneurysmal dilation of the abdominal & thoracic aorta Aortic rupture Stroke Blood enters and pressurizes a ‘false lumen’ Obstruction of aortic branches End organ malperfusion ** deformities ** Joint hypermobility Thumb sign: Thumb tip extends from palm of hand when thumb is folded into closed wrist Wrist sign: thumb and fifth finger of the hand overlap when grasping opposite wrist Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published June 28, 2020 on www.thecalgaryguide.com