Dr Taranpreet Kaur
Sickle Cell Anemia is an inherited disorder of hemoglobin caused by the inheritance of the Sickle cell gene. The sickle cell gene causes the substitution of a single amino acid in the beta globulin chain of hemoglobin molecule leading to the formation of an abnormal hemoglobin HbS.
Burden of sickle cell anemia
Approximately 3,00,000 infants every year are born with Sickle Cell disease worldwide. About 50-80% of them die before their fifth birthday. India has the second highest burden of Sickle cell Disease affected individuals after Africa. The disease is more common although not restricted to the tribal population due to endogamous practices and consanguineous marriages and the prevalence varies from 5-40%. However, the exact numbers of the affected individuals are not available due to the paucity of data.
Normally, the red blood cells present in our blood are rounded disc-shaped, and can easily mold themselves to pass through narrow capillaries. But the presence of HbS causes the red blood cells to be transformed into Sickle-shaped cells during the conditions of stress like infections, cold climate, dehydration, surgery or medical illness and Low oxygen states. These sickle cell-shaped red blood cells are rigid and cannot pass through the narrow blood vessels and can often stick to the surrounding cells and clog the blood vessels causing Vaso-occlusive crisis leading to pain in bones, chest, or abdomen. This can also lead to other lethal complications such as Stroke (blockage of blood flow in the brain), Intestinal ischemia (blockage of blood flow in the intestines), Anemia and auto-destruction of spleen.
It is a genetically inherited disease that is autosomal recessive in inheritance. Autosomal recessive means that if the person is having only one diseased gene (Sickle cell gene), then he will be called as having the Sickle cell trait or a carrier and will be leading a normal asymptomatic life. But if one is having both genes then the disease will be manifested.
* If both the father and mother are the carriers i.e., having a single gene for Sickle cell disease, then there is a 25% chance of having a child with Sickle cell disease, a 25% chance of having a normal child, and 50% chances of having only the carriers.
* If only one parent is the carrier of Sickle cell Disease, then 50% of children will be the carriers and 50% will be normal.
* If one parent is having Sickle cell disease and the other is normal, then 100% of children will be the carriers.
* If one parent is having sickle cell disease and the other parent is a carrier, then 50% of children will be having Sickle cell disease and 50% will be carriers.
* If both parents are having sickle cell disease, then 100% of children will be having sickle cell Disease.
Presently the only cure for patients with Sickle cell Disease is a Hematopoietic Stem cell transplant. But as this is a costly procedure, not many people can afford this. There are various drugs available for the treatment that are mainly to reduce the need for Blood transfusion and improve blood flow. During acute painful crises, many patients need painkillers and Blood transfusions.
Sickle cell anemia can be prevented by adopting the following practices:
* Pre-marital screening and counseling. A simple blood test can detect whether the presence is the carrier or a diseased person. As a person who is a carrier of sickle cell disease will not be having any disease features, so many times they go unnoticed and if both males and females are the carriers, then there are chances of birth of a child with SICKLE CELL DISEASE.
* Adolescent screening and awareness. Conducting awareness and screening camps for adolescents in schools and colleges can also prove to be helpful in prevention.
* Community-level awareness camps
* Screening of all the family members in case of detection of a case of Sickle cell Disease or a Carrier in the family.
* Foetal Screening: If both the parents are detected to be the carriers during antenatal screening, then the screening of the fetus can be done at 11-14 weeks of pregnancy and if found to have Sickle cell disease, then medical termination of pregnancy can be performed after consent of parents.
It is important to remember that being a carrier of Sickle cell disease is not a disease and they should not be cursed or discriminated against.
(The author is Assistant Professor, Department of General Medicine, AIIMS Jammu)
Dr Taranpreet Kaur