Three cases of Hb Q-H disease found in a Cantonese family.

Hemoglobin (Hb) Q-Thailand, also known as G-Taichung, Mahidol, Kurashiki-I and Asabara, is an α-globin chain variant that results from a point mutation (GAC→CAC; Asp→His) at codon 74 of the α1-globin gene on chromosome 16p with a leftward single α-globin gene deletion (-α(4.2)). Co-inheritance of Hb Q-Thailand with α-thalassemia (mainly --(SEA)) results in thalassemia intermedia, termed Hb Q-H disease.