Alpha thalassemia and the hematology of homozygous sickle cell disease in
childhood
MC Stevens, GH Maude, M Beckford, Y Grandison, K Mason, B Taylor, BE Serjeant, DR Higgs, H Teal and DJ Weatherall
alpha Thalassemia modifies the hematologic expression of homozygous sickle
cell (SS) disease, resulting in increased total hemoglobin and HbA2 and
decreased HbF, mean cell volume, reticulocytes, irreversibly sickled cells,
and bilirubin levels. The age at which these changes develop in children
with SS disease is unknown. Ascertainment of globin gene status in a large
representative sample of children with SS disease has afforded an
opportunity to study the hematologic indices in nine children homozygous
for alpha thalassemia 2 (two-gene group), 90 children heterozygous for
alpha thalassemia 2 (three-gene group), and 167 children with a normal
alpha globin gene complement (four-gene group). The two-gene group had
significantly lower mean cell volumes from birth, higher red cell counts
from one month, lower reticulocytes from three months, and higher HbA2
levels from one year, as compared with the four-gene group. Children with
three genes had intermediate indices but resembled more closely the
four-gene group. Differences in total hemoglobin or in fetal hemoglobin
between the groups were not apparent by eight years of age. The most
characteristic differences of the two-gene group were the raised
proportional HbA2 level and low mean cell volume, the latter having some
predictive value for alpha thalassemia status at birth.
Volume 67,
Issue 2,
pp. 411-414,
02/01/1986
Copyright © 1986 by The American Society of Hematology
