Haemoglobin H disease due to (– –SEA) α‐globin gene deletion and α2‐codon 30 (ΔGAG) mutation: a family study

A Chinese family in which two siblings suffer from haemogloblin (Hb) H disease due to (– –SEA) α‐globin gene deletion and α2‐codon 30 (ΔGAG) mutation is described. Both siblings are transfusion‐independent and have survived to adulthood. In contrast to previous report of hydrops fetalis associated with ζ‐α‐thal‐1 and α2‐codon 30 (ΔGAG) mutation, the ζ‐globin genes are intact in the two siblings, which most probably alleviates the γ‐chain excess and protects the fetus from severe anaemia. Correlation of genotype with phenotype in Hb H disease is important for genetic counselling, especially in the antenatal setting.