TYPE | Malay-2 Ggamma(Agammadeltabeta)°-Thal (see Fig. 16) | ||
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CAUSE | A large deletion that removes the Agamma, delta, and beta genes. The 5' end of the deletion is between the AhaIII and ApaI sites, 0.2 to 0.4 kb 5' to the Agamma gene and the 3' end is beyond sequences 17 to18 kb 3' to the beta gene. | ||
DETECTION | Gene mapping with different enzymes and probes. | ||
PHENOTYPE | The homozygote has a moderate anemia with a thalassemia intermedia-like phenotype; the hematological data are: Hb 11.8 g/dl; Hb F 100% (contained Ggamma chains only); PCV 0.33 l/l; RBC 4.98 x 1012/l; MCV 67; fl; MCV 23.7 pg; MCHC 35.5 g/dl; reticulocytes 3%. He had jaundice, hepatosplenomegaly, and thalassemic RBC morphology. The peripheral blood smear was characterized by a mild anisopoikilocytosis, hypochromia, and target cells. | ||
DISTRIBUTION | The proband was an adopted, 11-year-old Malay boy, without known relatives; he is homozygous for the deletion. |
REFERENCES | |||
1. | George, E., Faridah, K., Trent, R.J., Padanilam, B.J., Huang, H.J., and Huisman, T.H.J.: Hemoglobin, 10:353, 1986. |