Chapter 15.1, Problem 4CYP

Summary Introduction

To explain:

The higher incidence of sickle-cell disease in populations subject to malaria.

Given:

The relationship between the increased incidence of sickle cell disease with malaria.

Introduction:

Sickle-cell disease is an autosomal recessive disease which was first described by Harrick in 1910 and it is caused by haemoglobin S. A single gene mutation in the nucleotide base sequence in chromosome 11 causes the replacement of sixth amino acid the glutamic acid by valine in the beta chain of normal haemoglobin and changes it into haemoglobin S. This makes the normal red blood cells to sickle shaped. As a recessive gene disease, the presence of two faulty genes from both the parents, the individuals get affected by the disease. The heterozygote individuals with one defected gene do not produce the disease completely as well it offers resistance to the malarial infection.