The Hb H Disease Genotypes in Southern China

Abstract We report the genetic data of 435 patients with Hb H (β4) disease who presented at our center between 2005 and 2012. Our results showed that all patients had the Southeast Asian deletion (- -(SEA)) on one allele. The -α(3.7) (rightward) deletion was the most common on the other allele, followed by the -α(4.2) (leftward) deletion, Hb Constant Spring (Hb CS, α142, Term → Gln; HBA2: c.427T > C) and Hb Quong Sze [Hb QS, α125(H8)Leu → Pro; HBA2: c.377T > C] mutations. Two rare point mutations, α31(B12)Arg → Lys; HBA2: c.95G > A and Hb Zurich Albisrieden [α59(E8)Gly → Arg; HBA1: c.178G > C], were also identified. Four patients had a concomitant β-thalassemia (β-thal) heterozygosity. Our results reflect the genetic heterogeneity of Hb H disease and the interaction between Hb H disease and β-thal trait in Southern China.