title: Three cases of Hb Q-H disease found in a Cantonese family.
abstract: 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. The aim of the present study was to identify Hb Q-H disease in a Cantonese family. The presence of the Hb variant was confirmed by cellulose acetate electrophoresis. DNA analysis, based on polymerase chain reaction and sequencing, was developed to identify the α(Q-Thailand) mutation and common α-thalassemia gene deletions. Three cases of Hb Q-H disease and two Hb Q-Thailand carriers were found in the family. The 3-day-old proband with Hb Q-H disease did not show anemia (Hb 144 g/l), having 25.47% Hb F(Q) (α(Q)₂γ₂) in the total Hb; the other two cases of Hb Q-H disease manifested mild-to-moderate anemia. None required regular transfusions.
authors.affiliation: Guangzhou Kingmed Center for Clinical Laboratory, Guangdong, Guangzhou 510330, P.R. China. huzh@kingmed.com.cn
authors.forename: Chaohui
authors.initials: C
authors.lastname: Hu
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Jianghu
authors.initials: J
authors.lastname: Pan
authors.forename: Zengyu
authors.initials: Z
authors.lastname: Zeng
authors.forename: Saixiang
authors.initials: S
authors.lastname: Zhen
authors.forename: Ju
authors.initials: J
authors.lastname: Fang
authors.forename: Qingyi
authors.initials: Q
authors.lastname: Zhu
mesh_terms: D000293:Adolescent; D001483:Base Sequence; D002648:Child; D002681:China; D005006:Ethnicity / Q000235:genetics*; D005190:Family; D005260:Female; D006455:Hemoglobins, Abnormal / Q000235:genetics*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D017085:alpha-Thalassemia / Q000235:genetics*
chemical_list: D006455:Hemoglobins, Abnormal; C049214:hemoglobin Q Thailand