Background
Heterozygotes of HPFH and δβ thalassemia are clinically asymptomatic or have mild hemoglobin (Hb) values. However, when both HPFH and δβ-thalassemia are coinherited with heterozygous β-thalassemia, patients may progress to a clinical phenotype of thalassemia intermedia or thalassemia major. The
Conclusion
In Fujian Province, the prevalence of common β-globin gene cluster deletions was 0.04%. What's more, the most common β-globin cluster deletions are the Chinese G γ(A γδβ)0 and SEA-HPFH.
Methods
Multiplex ligation-dependent probe amplification (MLPA) and Gap-PCR were used to screen for three β-globin gene cluster deletions: Chinese G γ(A γδβ)0 thalassemia and Southeast Asia HPFH (SEA-HPFH) deletion and 1357 bp deletion (NG-000007.3:g.69997-71353 del 1357).
Results
A total of 142 patients with HbF (≥10%) were enrolled to characterize the molecular basis of β-globin gene cluster deletions in our study; 22 cases 0.04% (22/55 001) were definitively diagnosed with β-globin gene cluster deletions. Ten cases were heterozygous for the Chinese G γ(A γδβ)0 -thal mutations, 10 cases were heterozygous for SEA-HPFH, and one case was compound heterozygous for SEA-HPFH and the α-thal mutation. The 1357 bp deletion (NG-000007.3:g.69997-71353 del 1357) was detected in one case. Moreover, the hemoglobin A2 levels in patients who were heterozygous for Chinese G γ(A γδβ)0 -thal were statistically lower than in cases with SEA-HPFH deletion(p < 0.05).