Sickle-cell disease in a British urban community.

Seventy cases of sickle-cell disease were identified in the London Borough of Brent from records dating back to 1962. All but three were still alive and, with one exception, were recalled for confirmation of the diagnosis and to provide personal and family histories. The group consisted of 22 individuals with homozygous sickle-cell anaemia (Hb SS), 12 with sickle-cell/beta-thalassaemia double heterozygosity, 34 with sickle-cell/haemoglobin C disease (Hb SC), and two with the combination of haemoglobin S and hereditary persistence of fetal haemoglobin. They were predominantly of West Indian origin, more than half had been born in Britain, and most were aged under 25. The records for 304 patient admissions between 1962 and 1979 were analysed. There were 199 sickle-cell-disease-related admissions, 61 unrelated to sickle-cell disease, and 44 for pregnancy or its complications. Admissions per patient-year averaged less than one, except for children with Hb SS under the age of 5 years, who were admitted more frequently. The commonest reasons for admission were painful crises (74% of all admissions) and the "chest syndrome" (21%). There were four pneumococcal infections, all in children with Hb SS under the age of 8 years; all recovered. Three patients, aged 10, 15, and 50 years, died. The two children with Hb SS died in their sleep without gross evidence of sickling at necropsy. Multiple brain infarcts were found at necropsy in the 50-year-old woman with Hb SC who, having survived nine uneventful pregnancies, succumbed to an infection after cryosurgery to the cervix. Obstetric records were available for 18 term pregnancies in 11 women. Three antenatal sickling crises and three postpartum thromboembolic complications were encountered. There were no maternal or perinatal deaths. Fifteen asymptomatic individuals with sickle-cell disease were diagnosed as a result of routine screening procedures. There are likely to be many such individuals currently undiagnosed in the community. They urgently need identification because of their increased risks from pregnancy, surgery, and infection.