The following statement was issued by Graham Serjeant, chairman, Sickle Cell Trust (Jamaica). This week is being observed as 'Sickle Cell Awareness Week'.

People get sickle-cell disease by inheriting genes for abnormal haemoglobin from both parents and this occurs once in every 150 births in Jamaica. A carrier state for abnormal haemoglobin genes, called the 'trait', does occur in 375,000 Jamaicans: 10 per cent or 250,000 have the gene for sickle-cell haemoglobin (HbS), 3.5 per cent or 87,500 have the gene for HbC and 1.5 per cent or 37,500 have the gene for beta thalassaemia. People carrying these genes are usually well and it is incorrect to state that 375,000 Jamaicans have a disease. They do not, but they do carry a change in the blood which, if inherited from both parents, results in a child with sickle-cell disease.

Inherited

In these days of preventive medicine, it is better and cheaper to prevent disease than to treat its effects. This is clear in the increasing awareness of obesity causing high blood pressure, diabetes, and other degenerative conditions. Sickle-cell disease is inherited, and cannot, at the moment, be cured, but it can be prevented. In Bahrain, where the disease is common, screening of persons before marriage has halved the frequency of births of children with sickle-cell disease. This has now been made mandatory by a royal decree that no one can marry without being tested and counselled on sickle-cell disease. If both prospective partners carry genes placing them at risk of having an affected child, the families may still proceed but they have been informed of the risks. A similar royal decree has now been issued for the Kingdom of Saudi Arabia.

Both are highly-structured societies with a tradition of arranged marriages. Arranged marriages are not common in Jamaica but the underlying message is the same. If persons carrying the gene declined to have relationships with other carriers, there would be no more sickle-cell disease.