Hb H (β4) disease is the most common form of thalassemia intermedia. Two main types of Hb H disease, deletional and nondeletional, are characterized. Patients with nondeletional Hb H disease are usually more anemic with organomegaly; some may require regular blood transfusions and even be as severely affected as Hb H hydrops fetalis. However, there is no clear genotype-phenotype correlation associated with this severe clinical syndrome as patients with identical genotypes do not necessarily show the same severity. In this report, we described two nondeletional Hb H-Hb Quong Sze [α125(H8)Leu→Pro, CTG>CCG (α2)] disease individuals in a family who presented with phenotypic variability.