Different molecular defects of ^Gγ (^Aγδβ)°‐thalassaemia in Thailand

Abstract

DNA from members of 2 Thai families with conditions considered to be δβ‐thalassaemia were studied by using restriction endonuclease DNA mapping. The propositus in family A is a double heterozygote for β‐thalassaemia and δβ‐thalassaemia. DNA analysis reveals a deletion of the β‐globin gene cluster starting at the area between the Sac I and Eco RI sites near the 3′ end of the G γ‐gene and extending through the A γ‐, δ‐ and β‐genes to an unknown extent downstream. In family B, the propositus is δβ‐thalassaemia/Hb E. Deletion of the β‐globin gene cluster begins in the large intervening sequence of the A γ‐gene and removes both δ‐ and β‐genes downstream. © Munksgaard 1987