epidemiology

Last reviewed 01/2018

Sickle cell disease affects 1 in 2000 live birth and is considered as the most common serious genetic condition in England. The birth prevalence may reach as high as 1 in 300 in some urban areas (1).

  • according to estimates there are 240,000 healthy carriers of the sickle gene variants with over 12,500 having a sickle cell disorder (2)
  • highest prevalence of the disease was seen in people of African or West Indian (Caribbean) descent with
    • sickle cell trait seen in 1 in 10 people
    • sickle cell disease in 1 in 200 people
  • sickle disease is also seen in people from the eastern Mediterranean, the middle east, India and Pakistan (2)

It is estimated that 100,000 homozygotes are born each year in Africa, 1500 in the USA, 700 in the Carribean, and 140 in the UK

High frequency of the mutant gene is seen in Africa where sickle-cell trait provides resistance against falciparum malaria during the early childhood resulting in survival of the host and subsequent transmission of the abnormal haemoglobin gene (although inheritance of two HbS genes does not provide protection) e.g. - the prevalence of the sickle-cell trait can be as high as 10% - 40% across equatorial Africa and reduces to 1% - 2% on the north African coast and <1% in South Africa (3)

The prevalence of sickle-cell anaemia at birth is determined by the frequency of the carrier state. e.g. – in Nigeria 24% carry the mutant gene and the prevalence of sickle-cell anaemia is about 20 per 1000 births (3)

Sickle cell anaemia is a significant problem in the black population of the USA and the Caribbean.

HbS is also common in Cyprus, Greece, Italy, the Middle East and in populations who originate from these areas.

However population migration has made SCD an important disease in a majority of countries (3).

.Reference:

Related pages:

high risk groups for sickle cell disease