Question

Marfan's syndrome (MFS) is an inherited disorder with characteristic skeletal, dermatological, cardiac, ocular and dura mater malformations. MFS is caused by a variety of mis-sense mutations in the gene encoding for fibrillin 1. The pattern of transmission is autosomal dominant with complete penetrance. Phenotype varies within and between families with the same genetic abnormality, leading to protean and variable manifestations of the condition in given individuals One symptom that is found in patients with Marfan's syndrome is the presence of a dural ectasia hernia in the spinal cord. For the following patients, explain where the hernia is located and how it causes the symptoms in the patient A. Patient A cannot feel touch and pressure in their right leg but has normal movement of their right arm B. Patient B cannot move their left abdominal muscle but feel pain and temperature in their right neck C Patient C cannot move their right arm D. For Patient D above, an additional test was ran and it showed that when her right hand touched a hot plate (>45 back quickly but she still was unable to feel anything. Explain where the hernia is located but why this movement occurred and diagram the pathway that caused her hand to move. it snapped Another symptom of MFS is the high prevalence of high myopia due to lens dislocation. (A) What structures that control lens shape are affected by MFS? (B) How does failure of these structures couse the myopia in patients with MFS?

Answer 1