Items 31-34

A 17 year-old woman died of a sudden rupture of an aortic aneurysm during a basketball game. She was tall wit long arms and legs and hyperextensibility in her digits. Her parents were apparently normal.

31. The most likely cause of death was from

(A) scurvy
(B) Marfan’s syndrome
(C) familial hyperlipedemia
(D) lathyrism
(E) congenital heart disease

32. The extracellular matrix molecule defective or deficient in this disease is most of most.

(A) fibronectin
(B) type II collagen
(C) hyaluronic acid
(D) type I collagen
(E) fibrillin

33. The genetic character of the mutation in this particular case was.

(A) spontaneous new
(B) autosomal dominant, full penetrance
(C) autosomal recessive
(D) sex-linked recessive
(E) sex-linked dominant

34. The defective gene in this case is located on which chromosome.

(A) 11
(B) 13
(C) 15
(D) 21
(E) X

ANSWERS AND TUTORIAL ON ITEMS 31-34

The answers are; 31-B;32-E;33-A 34-C. A single autosomal gene defect on chromosome 15 leads to formation of qualitatively defective (or quantitatively deficient) fibrillin and Marfan’s syndrome, a disease inherited as an autosomal dominant mutation. Sicne the parents were apparently normal, this patient represented a new spontaneous mutation. Marfan’s syndrome patients are tall and thin with long extremities and hyperextensible digits. Aortic aneurysm is a common cause of death. Defects in the extracellular matrix of the media of large blood vessels such as the aorta can lead to aneurysms and fatal rupture, the most common cause of death in Marfan’s syndrome. Forensic Comparison Microscopes