RT Journal Article
SR Electronic
T1 Dominant β-thalassaemia with unusually high Hb A2 and Hb F caused by βCD121(−G) (HBB:c.364delG) in exon 3 of β-globin gene
JF Journal of Clinical Pathology
JO J Clin Pathol
FD BMJ Publishing Group Ltd and Association of Clinical Pathologists
SP 511
OP 513
DO 10.1136/jclinpath-2019-206308
VO 73
IS 8
A1 Kritsada Singha
A1 Rossarin Karnpean
A1 Goonnapa Fucharoen
A1 Supan Fucharoen
YR 2020
UL http://jcp.bmj.com/content/73/8/511.abstract
AB We describe a dominant β-thalassaemia caused by a deletion of G at nucleotide position 364 in exon 3 of the β-globin gene. The heterozygosity of this mutation was found in a 36-year-old Thai patient who had moderate hypochromic microcytic anaemia with haemolytic blood picture. Haemoglobin (Hb) analysis revealed relatively higher Hbs A2 (6.8%) and F (4.7%) as compared with those of β0-thalassaemia (n=278) and β+-thalassaemia (n=55) carriers in our series. Secondary structure prediction of the elongated β-globin chain showed that the α-helix at the C-terminal is disrupted dramatically by the random coil and β-sheet, which should result in a highly unstable β-globin variant, undetectable in peripheral blood and a dominant clinical phenotypic feature.