Mutation in the beta globin gene results in the formation of HbS instead of HbA which causes the haemoglobin to form sickle shapes.
Homozygous SS gene results in sickle cell anaemia.
Heterozygosity gives the sickle cell trait although no disability occurs vasoocclusive crisis can occur in hypoxic conditions.
Anaemia, jaundice, splenomegaly, heart failure, leg ulcers, renal failure
Symptoms present from the 3rd month of life as HbF is present until after time
which compensates for the reduction in haemoglobin capacity. Bone pain, cerebral infarction, retinal ischaemia, priapism
Bloods: FBC shows anaemia, U&E
Blood film: Target Cells and Sickle Cells
Hb electrophoresis: HbS 80-90%. Hb F may be raised.
Conservative: Prevent/minimize triggers for hypoxaemia and acidosis
Medical: Folic acid, prophylactic antibiotics, blood transfusion, bone marrow
transplant, Hydroxycarbamide to increase HbF.
Variable depending on combination of genes inherited and available supportive treatment
Infarcted organs: bone, spleen, kidneys, CNS, pulmonary hypertension. Proliferative retinopathy. Developmental and psychosocial problems