Abstract:

Objective To investigate the genotypes and hematological manifestions of HbH patients among child⁃bearing adults in Jiangxi province，and to provide guidence for prenatal diagnosis and genetic counsel⁃ ing. Methods Routine blood test，hemoglobin electrophoresis，and thalassemia genetic testing were performed on 9883 child ⁃bearing adults admitted to Jiangxi Maternal and Child Health Hospital. Information of genotypes and hematological parameters of these HbH patients was collected and analyzed，and 5 HbH families in need of thalas⁃ semia prenatal diagnosis received further detection at the appropriate gestational ages. Thalassemia genetic testing was performed by Gap⁃PCR，Dot⁃RDB and Sanger sequencing，respectively. Results Thirty⁃four cases with HbH disease（0.34%）were detected among 9883 subjects，with nineteen cases as ⁃3.7α /⁃SEA（57.58%），nine cases as ⁃4.2α/⁃SEA（27.27%），one case as αWSα/⁃SEA，one case as αCSα/⁃SEA，one case as αCD61（AAG>TAG）α/⁃⁃SEA，and three cases as compound β⁃thalassemia and deletional HbH. Routine blood test revealed that all 34 cases showed microcytic hypochromic hematological features. The HbH⁃WS case showed normal hemoglobin（Hb），while the other 33 cases with HbH disease demonstrated mild or moderate anemia. Hemoglobin electrophoresis analysis revealed the decreased HbA2 level in 31 patients with HbH disease and the increased HbA2 level in 3 patients with com⁃ pound HbH disease and β⁃thalassemia. A total of 30 cases with HbH disease showed the presence of HbH and 19 cases of Hb Bart′s via hemoglobin separation. Conclusion Deletional HbH disease is more common than the non⁃ deletional among child⁃bearing adults in Jiangxi Province，with ⁃3.7α/⁃⁃SEA as the most prevalent genotype. The clinical manifestions of HbH disease vary with individuals，most of which are mild or moderate microcytic hypo⁃ chromic anemia. Genetic testing is nessesary for the diagnosis of HbH patients and prenatal diagnosis is an effective method for these HbH patients at risk of offspring birth with clinically affected thalassemia

Key words:

thalassemia, hemoglobin H disease, Jiangxi province, prenatal diagnosis