Chapter 101. Hemolytic Anemias and Anemia Due to Acute Blood Loss (Part 6) doc

Hemolytic Anemias and Anemia Due to Acute Blood Loss Part 6 Peripheral blood smear from patients with membrane-cytoskeleton abnormalities.. Elliptocytosis, with both alleles of the α

Chapter 101 Hemolytic Anemias and Anemia

Due to Acute Blood Loss

(Part 6)

Peripheral blood smear from patients with membrane-cytoskeleton

abnormalities A Hereditary spherocytosis B Hereditary elliptocytosis, heterozygote C Elliptocytosis, with both alleles of the α-spectrin gene mutated

[From L Luzzatto, in J Gribben and D Pravan (eds): Molecular Hematology, 2d edition Oxford, Blackwell, 2005; with permission.]

Table 101-3 Inherited Diseases of the Red Cell Membrane-Cytoskeleton

mal Location

Protei

n Produced

Disease(

Certain Mutations

Comment

s

(Inheritance)

SPTA1

α-Spectrin

HS (recessive)

Rare

(dominant)

Mutations

of this gene account for about 65% of HE More severe forms may be

coexistence of an otherwise silent mutant allele

β-Spectrin

HS (dominant)

Rare

(dominant)

Mutations

of this gene

account for

~30% of HE, including some severe forms

in

HS (dominant)

May account for majority of HS

SLC4A

1

3 (anion channel)

HS (dominant)

Mutations

of this gene may account for

~25% of HS

st Asian ovalocytosis (dominant)

Polymorp hic mutation (deletion of 9 amino acids); clinically

asymptomatic; protective against

Plasmodium falciparum

EPB41

1p33-p34.2 Band

4.1

HE (dominant)

Mutations

of this gene account for about 5% of HE, mostly with prominent

morphology but

no hemolysis in heterozygotes; severe hemolysis

in homozygotes

EPB42

15q15-q21 Band

4.2

HS (recessive)

Mutations

of this gene account for about 3% of HS

s antigen nonspherocytic

hemolytic anemia

associated with total loss of all

Rh antigens

Note: HS, hereditary spherocytosis; HE, hereditary elliptocytosis