Hemoglobin H disease caused by two gene deletions

ABSTRACT

1. A white Brazilian woman not of Asian origin was found to have Hb H disease of moderate severity. 2. Gene mapping demonstrated that the disease was caused by the association of two abnormal alfa-globin gene clusters on chromosome 16 one with a deletion which removed the two function alfa genes and the other carryng the 3.7-Kb rightward deletion, which leaves functional alfa gene. 3. These data ilustrate the necessity for systematic molecular approaches to the diagnosis of this heterogeneous group of diseases