August 20, 2015 - Sickle Cell Disease

Question 1

Mechanism of Sickle Cell Disease

Answer 1

A single nucleotide change in the beta-globin gene from glutamic acid to valine. This is known as Hemoglobin S - a₂B₂^6Glu-Val. This results in abnormal hemoglobin function.

Question 2

Sickle Cell Nomenclature

Answer 2

HbSS - homozygous for disease

HbSA - heterozygous (asymptomatic)

* Can also be combined with other variant forms *

HbSC

HbSß-thalassemia

Question 3

Sickle Cell Diagnosis

Answer 3

Can be diagnosed with a peripheral blood smear or through molecular methods. Usually diagnosed between 6-12 months old as it is the beta-globin gene.

Question 4

Oxygen and Sickling

Answer 4

A lack of oxygen causes the RBCs to polymerize and sickle. This is why under extreme exercise, sickling episodes may occur.