A Novel Deletion of ~ 2.8 Kb Removing the Entire Alpha 2-Globin Gene Observed in a Chinese Patient with Hb H

Most of recognized alpha-thalassemia mutations include deletions of one or both alpha-globin genes. Here we describe a newly detected alpha-thalassemia-2 deletion characterized by a small 2.8 kb deletion involving the a 2 globin gene. This deletion has thus far been observed in one Chinese subject with hemoglobin H disease. Its breakpoints were detected to lie between coordinates 32485 and 35381 of the alpha-globin gene cluster (NG_000006.1), with a total of 2,894 nucleotides deleted. It was designated as -alpha2.8 deletion. The proband is a compound heterozygote deletion of -SEA and -alpha2.8, and the patient displayed very mild hemoglobin H disease phenotype with hemoglobin 9.8 g/dL.