Sickle Cell Disease: Causes, Treatment, and Psychosocial Impact

Introduction

Sickle cell disease affects millions of people throughout the world. The disease is particularly prominent among sub-Saharan African populations, where incidence rates are very high. In the western and central African regions, for example, almost 25% of people carry the sickle cell trait, and 1 to 2% of babies are born with the disease. In Nigeria alone, approximately 45,000 to 90,000 newborn babies are identified with the condition every year. The disease is also common in South and Central American countries, Cuba, and in Mediterranean countries such as Greece, Turkey, and Italy. In Asia, India and Saudi Arabia have a high incidence of the disease.

In the United States, sickle cell disease presents a significant healthcare problem, with more than 70,000 cases and an average of 1,000 new babies born with the condition each year (CDC). More than two million people are thought to be genetically predisposed to the condition and carry the sickle cell trait. Of all ethnic groups in the United States, the African American population has the highest predisposition, with one in every 500 people identified with the disease and one in twelve carrying the sickle cell trait. The next ethnic group at risk is the Hispanic population, with an incidence rate of 1 in every 1,000 to 1,400 people (CDC). A brief overview of sickle cell disease, its treatment, and its psychosocial implications provides useful insight into this debilitating condition.

Sickle Cell Disease Etiology

Sickle cell disease refers to a group of genetic disorders that result in alteration of the hemoglobin structure and disruptions in the normal circulation mechanism. This produces symptoms ranging from intense and intermittent pain, anemia, and stroke, to a high risk for infections and severe organ damage due to disrupted blood supply. This is an inherited disorder; those identified with the most common form — sickle cell anemia (Hb SS) — have inherited one sickle cell gene from each parent. It is also possible for a person to inherit one sickle cell gene from one parent and a different type of abnormal gene from the other parent, resulting in a different form of the disease known as hemoglobin S thalassemia. People who inherit one sickle cell gene from one parent and a normal gene from the other have what is known as the sickle cell trait, but not sickle cell disease. Children born to such parents are at greater risk of developing the condition (Nemours Foundation).

Molecular studies show that the substitution of valine in place of glutamic acid at the 6th position of the beta chain changes the structure of the resulting hemoglobin in such a way that it elongates red blood cells into a sickle shape (Allan Platt). Thus the normally disc-shaped red blood cells are contorted into elongated, sickle-shaped cells. Due to their distorted shape, these red blood cells find it difficult to pass through blood vessels, resulting in blockages along narrow vessels. The result is severe pain caused by the blockage. Because the lack of blood supply also means a lack of oxygen, the cells of affected organs are at risk of hypoxia and subsequent organ damage. Furthermore, sickle cells have a significantly shorter lifespan compared to normal red blood cells. Normal red blood cells live up to 120 days, while sickle cells survive only 10 to 20 days, producing a condition known as anemia — a lower-than-normal red blood cell count (Nemours Foundation).