Sickle Cell Disease Complications

Abstract

Sickle cell disease (SCD) is an inherited, lifelong condition. The sickle mutation consists a single nucleotide change (GAT->GTT) in the sixth codon of exon 1 of the β-globin gene coding for the β-globin polypeptide of hemoglobin (Hb) (a2β2). This change results in replacement of the wild type glutamic acid residue by a valine residue in β-globin chain and the formation of the sickle Hb (HbS) in homozygotes for this mutation. Heterozygotes live a normal life. In SCD patients, sickle erythrocytes are rigid with decreased deformability and reduced life span resulting in hemolysis, vaso-occlusive disease, vasculopathy and subsequent inflammation and end organ damage. Sickle cell disease affects millions of people worldwide. Today, with proper health care, many SCD patients have a good quality of life (QoL) and are in fairly good health most of the time. These people can live up to their forties or fifties, or longer. Despite the ‘common’ underlying genetic basis and a similar pathophysiology, patients with SCD present a highly variable clinical phenotype due to Single Nucleotide Polymorphisms (SNPs) variability throughout the genome. Patients with SCD are at high risk for developing multisystem acute and chronic complications associated with significant morbidity and mortality.