Project Materials

SERUM SODIUM CONCENTRATION IN SICKLE CELL PATIENT

Chapter one

INTRODUCTION

1.1 Background of the Study.

Sickle cell disease (SCD) is a series of genetic diseases affecting the beta-hemoglobin chain. Normal haemoglobin consists of three types: haemoglobin A, A2, and F. In sickle cell disease, haemoglobin S has an aberrant beta globin chain encoded by a valine substitution for glutamic acid on chromosome 11 (Bunn, 2007).

This is an autosomal recessive condition. Sickle cell disease is a specific genotype in which a person gets one copy of the HbS gene and another gene that codes for a qualitatively or quantitatively defective beta globin chain. Sickle cell anaemia (HbSS) affects patients who are homozygous for the HbS gene, although heterozygous versions may combine HbS with genes coding for other types of defective haemoglobin, such as haemoglobin C, an autosomal recessive mutation that replaces lysine with glutamic acid.

Additionally, individuals can inherit a mix of HbS and β-thalassemia. β-thalassemias are autosomal recessive disorders that cause anaemia due to decreased or absent β-globin chains. Other genotype pairs are HbSD, HbSO-Arab, and HbSE (Meremiku, 2008).

Sickle haemoglobin in these illnesses causes affected red blood cells to polymerise under conditions of low oxygen tension, resulting in the distinctive sickle shape. Normal red cells exist in the bloodstream for roughly 120 days, but sickled red cells die after 10 to 20 days.

Because they cannot be regenerated quickly enough, the blood is chronically depleted of red blood cells, a disease known as anaemia.

Inflammation, endothelial abnormalities, and thrombophilia cause sickle cell accumulation in the microcirculation, resulting in ischaemia in end organs and tissues distal to the blockage (Hayes, 2004).