Clinical Features and Molecular Analysis of Hb H Disease in Taiwan

Abstract EN

Thalassemia is highly prevalent in Taiwan, but limited data are available about the association between genotypes and clinical manifestations in Taiwanese patients with Hb H disease.

Here, we studied α-globin gene abnormalities and clinical features in Taiwanese patients with Hb H disease.

Of the 90 patients, sixty-four (71.1%) were deletional and twenty-six (28.9%) were nondeletional Hb H disease.

The (- -SEA) type of α0-thalassemia mutation was detected in the majority of patients (>95%).

The most common genotype was (- -SEA/-α3.7), followed by (- -SEA/αcsα).

After further investigation of the genotype-phenotype correlation in 68 patients, we found that patients with nondeletional Hb H disease had more severe clinical features than those with deletional Hb H disease, including younger age at diagnosis, more requirement of blood transfusions, and larger proportion of patients with splenomegaly, hepatomegaly or jaundice.

This is probably a consequence of the lower hemoglobin levels and the higher Hb H levels.

The clinical severity was highly variable even among patients with an identical genotype, and the diversity was much more profound among patients with (- -/αcsα) genotype.

Therefore, predicting the phenotype directly from the genotype in Hb H disease remains relatively difficult in Taiwan.