What is sickle cell disease?
A group of disorders characterized by the presence onf an abmormal form of hemoglobin in erythrocytes. It is an autosomal recessive disorder, where valine replaces glutamic acid, meaning if both parents have the trait then there is a chance
Risk populations for SCD
people near the equator, it is believed the mutation has abeed a response to malaria and so sickle gene carriers have some advantage where maleria is present. African americans are most vulnerable.
Pathology of SCD
RBCs become sickle shaped, clump and stiffen. Make it difficult to flow through ciculation, they are fragile and turns into premature destruction of RBC if sickled. Deoxygenation, dehydration and extreme stress causes sickling.
clinical manifestations of SCD
classical manifestations of anemia, Jaundice, Pain, variable organ involvement which can cut off blood supply
Vasoocclusive in sickle cell
If not reversed it will result in ischemia, infarction of the organs. Extremely painful in joints.
Aplastic crisis in SC
profound anemia due to premature destruction and diminished erythropoesis.
Sequestration crisis in SC
critical only in young children, pooling of large amounts of blood in liver and spleen, can lead to cardiovascular collapse.
Rapid RBC destruction often caused by drugs, infection or virus.
Diagnostics of SCD
genetic history, hemoglobin electrophoresis, prenatal testing of chorionic villus, prenatal testing of amniotic fluid.