Drakoulakou O, Papapanagiotou E, Loutradi-Anagnostou A, Papadakis M
Laikon General Hospital, Center for Thalassemias, Athens, Greece.
Hum Mutat. 1997;9(4):344-7. doi: 10.1002/(SICI)1098-1004(1997)9:4<344::AID-HUMU7>3.0.CO;2-5.
delta-Thalassemia reduces the expected HbA2 percentage, altering the normal as well as the beta-thalassemia trait phenotype. An attempt to elucidate the molecular basis of delta-thalassemia in the Greek population, revealed two cases with unknown molecular defects that presented low levels of HbA2 (about 1.5%). DNA sequence analysis of delta-globin gene identified two "novel" mutations in the coding regions of the gene; the cd11 (GTC-->GGC) resulting in the substitution of valine for glycine (:HbA2-Pylos) and the cd85(TTT-->TCT) resulting in the substitution of phenylalanine for serine (:HbA2-Etolia). Because these mutations are localized at the helical positions A8 and F1 of the HbA2 respectively, they potentially cause molecular instability of the tetramer, thus leading to reduced HbA2 percentage.
δ地中海贫血会降低预期的HbA2百分比，改变正常以及β地中海贫血特征的表型。为阐明希腊人群中δ地中海贫血的分子基础，发现了两例分子缺陷不明且HbA2水平较低（约1.5%）的病例。对δ珠蛋白基因进行DNA序列分析，在该基因的编码区鉴定出两个“新”突变；cd11（GTC→GGC）导致缬氨酸替代甘氨酸（：HbA2 - 皮洛斯），cd85（TTT→TCT）导致苯丙氨酸替代丝氨酸（：HbA2 - 埃托利亚）。由于这些突变分别位于HbA2的螺旋位置A8和F1，它们可能导致四聚体的分子不稳定，从而导致HbA2百分比降低。
