A distant gene deletion affects beta-globin gene function in an atypical gamma delta beta-thalassemia.
We describe an English family with an atypical gamma delta beta-thalassemia syndrome. Heterozygosity results in a beta-thalassemia phenotype with normal hemoglobin A2. However, unlike previously described cases, no history of neonatal hemolytic anemia requiring blood transfusion was obtained. Gene mapping showed a deletion that extended from the third exon of the G gamma-globin gene upstream for approximately 100 kilobases (kb). The A gamma-globin, psi beta-, delta-, and beta-globin genes in cis remained intact. The malfunction of the beta-globin gene on a chromosome in which the deletion is located 25 kb away suggests that chromatin structure and conformation are important for globin gene expression.
D000328:Adult; D000818:Animals; D002872:Chromosome Deletion; D002906:Chromosomes, Human, 6-12 and X / Q000648:ultrastructure*; D004247:DNA / Q000032:analysis; D004262:DNA Restriction Enzymes; D005260:Female; D005786:Gene Expression Regulation; D005914:Globins / Q000096:biosynthesis / Q000235:genetics*; D006454:Hemoglobins / Q000032:analysis; D006579:Heterozygote; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D051379:Mice; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000235:genetics; D013789:Thalassemia / Q000097:blood / Q000235:genetics*
D006454:Hemoglobins; D005914:Globins; D004247:DNA; D004262:DNA Restriction Enzymes