chapter 24 - hemoglobinopathies

decreased production of globin chain

qualitative abnormality in hemoglobin may involve all of the ff except

• replacement of one or more amino acids in a globin chain

• addition of one or more amino acids in a globin chain

• deletion of one or more amino acids in a globin chain

• decreased production of a globin chain

polymerizes to form tactoid crystals

substitution of valine for glutamic acid at position 6 of the β chain of hemoglobin results in hemoglobin that"?

higher levels of Hb F are present

px with sickle cell disease (SCD) usually do not exhibit symptoms until 6 months of age because

folic acid

megaloblastic episodes in SCD can be prevented by prophylactic administration of

hemoglobin electrophoresis at acid pH

most definitive test for Hb S

substitution of lysine for glutamic acid at position 6 of the β chain

px

• presents with mild normochromic macrocytic anemia

• peripheral blood film

  • few target cells

  • rare nucleated RBCs

  • hexagonal crystals within & lying outside of the RBCs

which abnormality in the hemoglobin molecule is most likely?

px has Hb M

well-mixed specimen obtained for a CBC has a brown color

px — being treated for sulfonamide for a bladder infection

which of the following could explain the brown color?

25%

through routine screening, prospective parents discover that they are both heterozygous for Hb S

what percentage of their children potentially could have sickle cell anemia (Hb SS)?

vasoocclusion

painful crises in px with SCD occur as result of?

are insoluble in reduced, deoxygenated form

screening test for Hb S that uses a reducing agent, such as sodium dithionate, is based on the fact that hemoglobin that sickle?

homocygous/disease

DNA analysis documents a px that has inherited the sickle mutation in both β-globin genes.

the two terms that best describe this genotype are?

sub-saharan Africa

in which geographic area is Hb S most prevalent

Hb E

which hemoglobinopathy is more common in individuals of southeast Asian descent

Hb SG

Hb S compound heterozygotes exhibits the mildest symptoms

only homozygotes are symptomatic

unstable hemoglobin exhibit all of the following findings except

• globin chains that precipitate intracellularly

• heinz body formation

• elevated reticulocyte count

• only homozygotes are symptomatic

Hb CO

1 year old px of Indian ancestry

• presents with anemia

  • both parents claim to have “inherited anemia“ but can’t remember the type

• peripheral blood film

  • shows target cells

• hemoglobin solubility — negative

• alkaline hemoglobin electrophoresis

  • shows single band at “Hb C“ position

  • small band at “Hb F“ position

• acid hemoglobin electrophoresis — shows two bands

most likely diagnosis is?