ALPHA-THALASSEMIA AND STROKE RISK IN SICKLE-CELL-ANEMIA

In an effort to identify possible risk factors for stroke in Sickle Ce ll Anemia (Hb SS), we analyzed the distribution of alpha-globin gene d eletions in a group of Hb SS patients with and without stroke. The gro up with stroke consisted of 44 patients, (27 male, 17 female) with a m ean of 7.5 years at time of stroke. The control group (non-stroke) had 256 Hb SS patients (126 male, 130 female) with a mean age of 7.7 year s. There were 9 patients with heterozygous alpha-thalassemia in the st roke group (20.5%). In the control group, there were 93 patients with heterozygous alpha-thalassemia and 5 with homozygous alpha-thalassemia . The incidence of alpha-thalassemia in Hb SS patients without stroke (38%) was comparable to that reported for the African-American populat ion in general. The incidence in the stroke population (20.5%) was sig nificantly lower (P = 0.02) These results indicate that alpha-thalasse mia is associated with a lower risk of stroke in Hb SS. This observati on should be confirmed in studies involving larger numbers of patients . Possible protective effects of alpha-thalassemia are unknown but may be related to decreased hemolysis and more favorable theologic proper ties of red blood cells. (C) 1994 Wiley-Liss, Inc.