TYPE | Anglo-Saxon (epsilongammadeltabeta)°-Thal (see Fig. 17) | ||
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CAUSE | This condition is caused by a large deletion of 95.9 kb that removes DNA starting ~50 kb upstream from the epsilon gene to the second exon of the beta gene. | ||
DETECTION | Gene mapping with different enzymes and several probes. | ||
PHENOTYPE | This form of thalassemia is characterized by the absence of production of gamma-, delta-, and beta-globins. The proband had the following hematology: Hb 10.4 g/dl; PCV 0.32 l/l; RBC 3.81 x 1012/l; MCV 84 fl; MCH 27 pg; MCHC 32 g/dl; Hb F 52%; Hb A2 1.2%. At 1 year of age, the patient had no anemia but her red cells were hypochromic and microcytic. Hb A2 was 2.7% and Hb F 3.1%. The proband's father was of English origin and the mother of German descent. The father had the same abnormality; he was not anemic and only slightly hypochromic and microcytic. Similar features were found in seven other family members. | ||
DISTRIBUTION | Found in one Anglo-Saxon family. |
REFERENCES | |||
1. | Kan, Y.W., Forget, B.G., and Nathan, D.G.: N. Engl. J. Med., 286:129, 1972. | ||
2. | Orkin, S.H., Goff, S.C., and Nathan, D.G.: J. Clin. Invest., 67:878, 1981. |