Thalassemia Intermedia Due to Co‐inheritance of β0/β+‐Thalassemia and (– –SEA) α‐Thalassemia/Hb Westmead [α122(H5)His > Gln (α2)] in a Chinese Family

Abstract

Two brothers from a Chinese family with β‐thalassemia intermedia who harbor both α‐ and β‐globin gene defects are described. They are both compound heterozygous for codons 41/42 (− CTTT) β0‐thalassemia and nt ‐ 28 (A > G) β+‐thalassemia mutattions together with concurrent (– –SEA) α‐thalassemia (SEA) deletion. One sibling also harbors Hb Westmead, giving an unusual genotype of β0/β+‐thelassemia and (– –SEA) α‐thalassemia/Hb Westmead. With respect to the age at presentation and transfusion requirement, this subject shows a milder clinical phenotype than his brother, most probably explainable by the presence of Hb Westmead in addition to the SEA deletion, which causes a further amelioration of the α‐chain excess and hence a less severe disease. For areas with high prevalence of both α‐ and β‐thalassemia mutations, their interactions should always be considered in genotype phenotype correlation. Moreover, routine laboratory diagnostic strategy for non‐deletional α‐globin gene mutation in the Chinese may need to include Hb Westmead, as it is common α‐globin gene mutation in our population apart from Hb Constant Spring and Hb Quong Sze.