曾报道一例β地中海贫血患者β地贫基因的克隆化分离与DNA序列分析。发现分离的β地贫基因在β珠蛋白基因密码子41-42中缺失四个核苷酸(TCTT)。它应导致β°地贫,但临床资料表明患者属β~+地贫。因此另一个β地贫基因必定是β~+地贫基因.经过RFLP分析,发现这个未知β地贫基因的染色体属单体型2,而与单体型2相关的β地贫基因可以是β~(41-42-TCTT)、β~(17)(A→T)‘β~(-28)(A→G)β~(71-72)(+A)及 A case of β-thalassemia β-thalassemia gene cloning and DNA sequence analysis were reported. The isolated beta thalassemia gene was found to lack four nucleotides (TCTTs) in the beta globin gene codons 41-42. It should cause β ° thalassemia, but the clinical data show that the patient is β ~ + thalassemia. Therefore, the other β thalassemia gene must be β ~ + thalassemia gene.Through RFLP analysis, the chromosome of this unknown β thalassemia gene is found to be haplotype 2, and β thalassemia gene associated with haplotype 2 may be β Β - (41-42-TCTT), β ~ (17) (A → T) ’β ~ (-28) (A → G) β ~ (71-72) (+ A)