[Analysis of phenotypes of Hb J-Bangkok and concomitant thalassemia]

To analyze the hematological phenotypes of Hb J-Bangkok and concomitant thalassemia.

In total 72 397 samples were screened by using capillary electrophoresis. Samples with Hb J-Bangkok were identified by DNA sequencing and analysis of red blood cell parameters. Gap-PCR and PCR-reverse dot blotting (PCR-RDB) were used for analyzing the thalassemia genes.

Thirty one cases of Hb J-Bangkok were identified, all of which were heterozygotes. The hematological phenotype index (Hb, mean corpuscular volume, mean corpuscular hemoglobin, Hb J-Bangkok, Hb A₂) for male carriers of Hb J-Bangkok were (158±13.0) g/L, (90.1±2.3) fL, (31.1±2.5) pg, (51.3±0.7)% and (2.5±0.1)%, those for female carriers were (124±9.3) g/L, (93.3±4.9) fL, (31.1±1.6) pg, (50.9±1.1)% and (2.6±0.2)%, those for Hb J-Bangkok and an α^3.7 deletion were 124 g/L, 82.1 fL, 26.1 pg, 49.4% and 2.4%, those for Hb J-Bangkok and --^SEA deletion were (120±14.1) g/L, (67.7±5.7) fL, (20.5±2.6) pg, (50.1±1.9)% and (2.1±0.4)%, and those for Hb J-Bangkok and β-thalassemia-related variants were (134±11.3) g/L, (71.6±0.9) fL, (21.7±1.0) pg, (92.7±0.6)%, (5.5±0.8)%. No Hb A was found among the Hb J-Bangkok and concomitant β-thalassemia carriers.

Hb J-Bangkok heterozygotes have normal hematological phenotypes, though they may show different hematological characteristics when concomitant with different types of thalassemia, for which genetic counseling should be provided accordingly.