Sickle Cell Disease

Sickle cell disease (SCD) is a collective name for a series of serious inherited chronic conditions of sickle hemoglobin that can affect all systems of the body. It is one of the most common genetic conditions in the world and affects around 2-3% of the 210 million Nigerians in the double (SS) and (SC) forms.

Sickle Cell Disease is a group of inherited red blood cell disorders. Normal red blood cells are round like doughnuts, and they move through small blood tubes in the body to deliver oxygen. Sickle red blood cells become hard, sticky and shaped like sickles used to cut wheat. When these hard and pointed red cells go through the small blood vessels, they clog the flow and break apart. This can cause pain and damage and a low blood count, or anemia results in episodes of bone pain. The condition involves a change in the Haemoglobin - the red blood component of blood that carries oxygen in and out of tissues. Unlike normal red blood cells, the sickle cells are unable to function maximally in their role to carry oxygen in and out of tissues.  One little change at the B6 position of the beta chain of haemoglobin causes the hemoglobin to form long rods in the red cell when it gives away oxygen. These rigid rods change the red cell into a sickle shape instead of the round shape. The sickle red cells are constantly broken down living only for about 20- 52 days instead of the 120 days of a normal red blood cell and hence the anaemia.  It is a chronic disease yet incurable except by Bone marrow stem cell transplantation carried out only in specialized centers at a very expensive cost. Finding a matched donor is however not a very easy process.









How does one get sickle cell anemia or trait?

The abnormal hemoglobin from parents who may be carriers of the Sickle Cell trait (HbAS) or Sickle Cell disease (HbSS) is inherited. If one is born with sickle cell hemoglobin and it is present for life. If only one sickle gene is inherited, there is a sickle cell trait. If two sickle cell genes are inherited there is Sickle Cell disease.

Sickle cell is in many nationalities including African Americans, Africans, Arabs, Greeks, Italians, Latin Americans, and those from India. There are however differences in the genetic presentations.

How can one be tested?

A simple blood test called hemoglobin electrophoresis (it is phenotyping but generally called GENOTYPING in Nigeria) can be done by your doctor or local Sickle Cell Foundation. This test will tell if one is a carrier of the sickle cell trait or has the disease. 

Newborn Screening

Haemoglobin screening test can be performed as soon as a baby is born. The simple blood test will detect sickle cell disease or sickle cell trait and other normal or variant hemoglobin types. Other types of traits that may be discovered include Hemoglobin C trait (HbSC), or Hb S-Beta thalassaemia (Hb S-βthal).

What are the complications of Sickle Cell Disease (SCD)?

Acute chest syndrome: Signs include chest pain, coughing, difficulty breathing, and fever. It can appear to be similar to flu-like symptoms. However, it is important to see a consultant ASAP.

Aplastic crisis: This is when the bone marrow temporarily slows its production of red blood cells, usually due to infection with a virus called ParvovirusB19. This results in a severe drop in the red cell count and severe anaemia. Signs include paleness, fatigue, and rapid pulse.

Fever: Children with sickle cell disease are at increased risk for certain bacterial infections. A fever of 101° Fahrenheit (38° Celsius) or higher, could signal an infection. Children with sickle cell disease and fever should be seen by a consultant without delay.

Hand-foot syndrome (also called dactylitis): Painful swelling of the hands and feet, plus fever. It is most likely to occur in children under five. It is important that nursery and pre-school staff are aware of this to avoid false accusations of non-accidental injury.

Painful crises: These may occur in any part of the body and may be brought on by cold or heat or dehydration. The pain may last a few hours or up to 2 weeks or even longer, and may be so severe that a child needs to be hospitalized. It is important to listen to the young person who will come to know whether the pain is mild or moderate and will pass (where schools can promote school inclusion by permitting rest and re-integration into school later that day) or whether they need to go to the hospital.

Priapism: Painful and unwanted erection of the penis for a prolonged time of over three hours.

Chronic Leg Ulcers (CLU): Unhealing wounds on the legs. Wounds take a very long time to heal up and when they do, break out again after some time. The CLU is currently treated with the Compression Therapy method by SCHAF.

Splenic sequestration crisis: The spleen becomes enlarged by trapping the sickle-shaped red blood cells. This leads to fewer cells in the general circulation. Early signs include paleness, weakness, an enlarged spleen, and pain in the abdomen. It is important that nursery and pre-school staff are aware of this life-threatening event, as it is more likely in younger children.

Strokes: The higher risk is in children aged 2-10 years. Apply the FAST approach:

Facial weakness: can the person smile, or has their mouth or eye drooped?

Arm: can the young person raise both their arms above shoulder height?

Speech problems: can the person speak clearly and understand what you say?

Time: to dial the emergency number for an ambulance.

 

It can be difficult to differentiate the symptoms of stroke from those of a sickle crisis, where pain can result in restriction of movement. Children with SCD have a Transcranial Doppler Scan yearly from age 2 to assess the risk of stroke. 


References

www.sicklecelleducation.com

www.sicklecellanaemia.org

Youths- A Call to Action for a Preventive Approach to Sickle Cell Disease in Nigeria. Seventh Matriculation Lecture. Delivered at Achievers University, Owo on Thursday, 23rd January 2014. Prepared by A.G. Falusi.

A Parent Handbook for Sickle Cell Disease in Nigeria. Part I, 0-6yrs. A University of Ibadan publication with support from Children’s Hospital, Oakland Sickle Cell Centre and Centre for Global Health, University of Chicago. Prepared by B.Brown, A.G. Falusi& P.K. Jaudes. (ISBN: 978 978 937 257 7) 2013.

A Parent Handbook for Sickle Cell Disease in Nigeria. Part II, 6-18yrs. A University of Ibadan publication with support from Children’s Hospital, Oakland Sickle Cell Centre and Centre for Global Health, University of Chicago. Prepared by B.Brown, A.G. Falusi& P.K. Jaudes. (ISBN: 978 978 937 258 4) 2013.