In view of the known high prevalence of α-thalassemia in blacks and the reported abrogration of typical macrocytosis in patients who have a deficiency of folate or vitamin B12 with coexistent thalassemia, we analyzed α-globin genotypes in peripheral-blood leukocytes from 6 black patients with pernicious anemia, using restriction-endonuclease mapping. At the time of presentation, these patients had been remarkable for a lack of notable macrocytosis associated with their megaloblastic condition. 4 of the 6 patients were found to have one or two α-globin-gene deletions, and in a fifth patient the ratio of α- to β-globin-chain synthesis was abnormal, suggesting the existence in that patient of a non-deletion type of α-thalassemia. The occurrence of α-thalassemia and the gene frequency for α-globin-gene deletions were both significantly greater in this group of patients than in the black population at large. Coexistence of α-globin-chain deletions in black patients with pernicious anemia results in a normal or only slightly elevated mean cell volume, masking the macrocytic expression of megaloblastic anemia. Consequently, the diagnosis of pernicious anemia may be overlooked in black patients - a population for whom there may already be a low index of suspicion for this disease.
|Original language||English (US)|
|Number of pages||4|
|Journal||New England Journal of Medicine|
|State||Published - 1982|
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