Nonblack patients with sickle cell disease have African beta S gene cluster haplotypes
Z. R. Rogers, D. R. Powars, T. R. Kinney, W. D. Williams and W. A. Schroeder
Department of Pediatrics, University of Southern California School of Medicine, Los Angeles.
Of 18 nonblack patients with sickle cell disease, 14 had sickle cell
anemia, 2 had hemoglobin SC disease, and 2 had hemoglobin S-beta
o-thalassemia. The beta s gene cluster haplotypes that were determined in 7
patients were of African origin and were identified as Central African
Republic, Central African Republic minor II, Benin, and Senegal. The
haplotype Central African Republic minor II was present on the beta
o-thalassemia chromosome in 2 patients. None of 10 patients whose
alpha-gene status was determined had alpha-thalassemia-2. These data
strongly support the concept that the beta s gene on chromosome 11 of these
individuals is of African origin and that the alpha-gene locus on
chromosome 16 is of white or native American origin. The clinical severity
of the disease in these nonblack patients is appropriate to their haplotype
without alpha-thalassemia-2 and is comparable with that of black patients.
All persons with congenital hemolytic anemia should be examined for the
presence of sickle cell disease regardless of physical appearance or ethnic
background.
