The inability to attach proteins requiring a ...

[Anajune7]

The inability to attach proteins requiring a glycosylphosphatidy linositol (GPI) link to the membrane surface is found in:
 
  a. Paroxysmal nocturnal hemoglobinuria
  b. Hereditary spherocytosis
  c. Paroxysmal cold hemoglobinuria
  d. Hereditary elliptocytosis

Question 2

In most patients with hereditary spherocytosis, the condition is:
 
  a. Inherited as an autosomal dominant trait
  b. Inherited as an autosomal recessive trait
  c. Inherited as an X-linked recessive trait
  d. Acquired after viral infection

[CharlieArnold]

Answer to Question 1

ANS: A
Proteins missing on the surface of paroxysmal nocturnal hemoglobinuria cells are all linked by GPI to the membrane. This has led to identification of the PIGA (phosphatidylinosito l glycan anchor biosynthesis, class A) gene, which is mutated in paroxysmal nocturnal hemoglobinuria; this gene is located on the X chromosome.

Answer to Question 2

ANS: A
Most patients (75 of families) inherit hereditary spherocytosis as an autosomal dominant trait, although autosomal recessive forms exist.