MODULE 12                                                                Marfans Syndrome

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Go to the NCBI web site at http://www.ncbi.nlm.nih.gov/

Then navigate to the OMIN link and search for Marfan syndrome. The first hit to come up is OMIN reference number 154700 MARFAN SYNDROME; MFS. Open the link and begin to read. Answer the following questions at the bottom of this page.  Do not cut and paste, answer in your own words.  When you are finished print out just your answers and turn them in.

1. What chromosome is the gene for Marfans syndrome on?

2. What is the name of the protein/ gene that is effected?

3. Name the type of tissue effected.

4. What are the most obvious clinical features?

5. What percent of patients have been referred for orthodontic treatment?

6. Read the next few paragraphs carefully and note that aneurysm of the aorta and intracranial aneurysm are both mentioned.  Go to the Medline plus medical encyclopedia at http://medlineplus.gov/  and determine what an aneurysm is. Define the term under number 6 in your answers.  View the aneurysm illustration and make a brief diagram of it under number 7. in your answers.

8. What did Cistulli and Sullivan suggest that Marfans syndrome is associated with?

9. What has been reported about the lifespan of patients and what is the most common cause of death?

10 Under INHERITANCE determine what percentage of individuals arise as new mutations?

11. Go to the first molecular genetics link and determine where fibrillin is found with regard to cells and the body.

12. Under clinical management discuss the success or failure of the 2002 Gott report on aortic root replacement at Johns Hopkins Hospital from 1976 to 2002.

Now go to gene map link and determine the names for the two genes that flank the gene for fibrillin.

Do not forget to save your work and print out your answers and make your brief diagram of an aneurysm.!!

MODULE 12    Marfan syndrome answers

1. Chromosome 15

2. fibrillin-1 gene

3. connective tissue-  ( skeletal, ocular, cardiovascular)

4. Increased height, disproportionately long limbs and digits

5. About 70% of the patients had been referred for orthodontic treatment, mostly because of crowded teeth or extreme maxillary overjet (overbite).

6. Main Entry: an·eu·rysm
Variant(s): also an·eu·rism /an-y-riz-m/
Function: noun
: an abnormal blood-filled dilatation of a blood vessel and especially an artery resulting from disease of the vessel wall
- an·eu·rys·mal also an·eu·ris·mal /an-y-riz-ml/ adjective
- an·eu·rys·mal·ly /-/ adverb

7. diagram

8. Cistulli and Sullivan (1995) suggested that the Marfan syndrome is associated with a high prevalence of obstructive sleep apnea.

9. Murdoch et al. (1972) reported that life span in patients affected with the Marfan syndrome is markedly shortened and that most deaths are cardiovascular

10. About one-quarter of affected individuals arise as new mutations; a paternal age effect is present, on average, in sporadic cases.

11. Fibrillin is the major constitutive element of extracellular microfibrils and has widespread distribution in both elastic and nonelastic connective tissue throughout the body.

12. Gott et al. (2002) reported on a total of 271 patients with Marfan syndrome in whom aortic root replacement had been performed at the Johns Hopkins Hospital in the 24-year period from 1976 to 2000. Two hundred thirty-two patients had Bentall composite graft replacement of the aortic root, 15 received a homograft, and 24 had a valve-sparing procedure. Of the 232 Marfan patients who underwent elective aortic root replacement, there was no 30-day mortality. Two early deaths occurred among 36 patients who underwent urgent or emergent operation. Eighty-three percent of the patients were alive at the time of report.

Marfan