Donaldo Laurenceo, Sr., chairman of the Sickle Cell Foundation of Bermuda, offers a copy of a publication from a recent conference. *Photo by B. Candace Ray
Donaldo Laurenceo, Sr., chairman of the Sickle Cell Foundation of Bermuda, offers a copy of a publication from a recent conference. *Photo by B. Candace Ray
What is sickle cell?

Sickle cell disease is an inherited change in the blood.

The protein haemoglobin, which is responsible for the red colour of blood, is made slightly differently in sickle cell disease.

Normal adult haemoglobin (HbA) is replaced by the abnormal sickle haemoglobin (HbS).

Haemoglobin is used to carry oxygen in the body but when HbS gives up its oxygen, the units of HbS stick together forming long chains, which change the shape of red blood cells.

Normal red blood cells are round and flat like a saucer, but in sickle cell disorder, when the oxygen is removed, the cells become long and pointed like a sickle or scythe.

How do you get sickle cell?

It is inherited from your parents. You cannot catch it like the flu or measles.

If you inherit the sickle cell gene from one parent and the gene for normal (HbA) from the other, you have the sickle cell trait.

This is harmless and cannot become the disease. If you inherit the HbS gene from both parents, you have homozygous sickle cell disease or SS disease.

Other types of sickle cell disease may occur if your parents carry other abnormalities in the blood.

Why does it cause problems?

When oxygen is removed from (HbS), it forms fibres, which make the red cell stiff and deforms them into a sickle shape.  These deformed cells cannot travel down blood vessels normally and are destroyed quickly and block flow in blood vessels.

Rapid red cell destruction causes anaemia, jaundice, gallstones, and problems from a greatly expanded bone marrow. Blocking blood vessels may cause death of the tissue supplied by those blood vessels resulting in problems which may affect anywhere in the body, but especially the bone, lungs, spleen, skin, and brain.

Damage to the bone marrow may cause pain close to the joints, back, and abdomen, usually starting in childhood, and becoming more frequent and severe in adolescence and early adult life, and then improving and often ceasing after the age of 30 years.

Attacks may follow getting cold, going swimming, doing strenuous exercise, or suffering from infections, or emotional stress.

Does it only affect black people?

No, the sickle cell abnormality is widespread. It is very common in Equatorial Africa, and most of the sickle cell disease seen in the Americas, Caribbean, Bermuda and Europe is in persons of African origin.

However, the abnormality also occurs in Italy, Greece, Turkey, Saudi Arabia, and Central India.

All these areas have a history of malaria and persons with the sickle cell trait have some resistance to malaria.

Over the centuries, people with the sickle cell trait have been more likely to survive and pass on their genes, so the sickle cell trait has become more common in malarial areas.

The sickle cell trait protects against malaria, but sickle cell disease does not, and malaria is a common cause of illness and death among persons with sickle cell disease in Africa.

How can you find out if you have it?

You must have a blood test called haemoglobin electrophoresis.

Can the disease be cured?

No, the abnormality is built into the genes and cannot be changed.

Can the disease be treated?

Certainly, and many of the complications can be avoided or treated more effectively.

Most of the early causes of death can be prevented and both survival and the quality of life are improving.

Can the disease be prevented?

Yes, in several ways. If people with the sickle cell trait avoided having children with others with the sickle cell trait, there would be no more children with sickle cell disease.

One approach would be to educate the population on the inheritance of the disorder and offer screening so that everyone would know their genotype. People could then make informed decisions on whether to have children if they knew they were at risk of a child with sickle cell disease.

Another approach is antenatal diagnosis early in the pregnancy so that the families know whether the foetus has the disorder and then can decide whether to bring the pregnancy to term.

What is the outlook for someone with sickle cell disease?

The outlook is a lot better than in the past. Now, with the better treatment and understanding of the disease, persons with the condition are much more likely to survive and enjoy better health.

Many survive beyond 50-60 years, some into their late 70s. It should be remembered that although complications may occur, many ‘sicklers’ are well much of the time.

The period of greatest risk is early childhood, and much can be done to prevent mortality, but only if the diagnosis has been made at birth.

Early diagnosis is probably the single most important factor in improving survival in sickle cell disease.