【摘要】 目的分析中国人β地中海贫血核苷酸-28(nt-28)突变基因的临床和血液学特点,并了解是否可以通过基因型推断出其表现型的严重程度。方法将244例β地中海贫血个体分为β地中海贫血轻型组(167例)、中间型组(13例)和重型组(64例),分析其临床、血液学资料以及β地中海贫血突变基因、α地中海贫血基因型和Xmn-Ⅰ珠蛋白基因启动子Gγ158位点Xmn-I内切酶多态性。结果在β地中海贫血轻型组,21例为βnt-28地中海贫血杂合子,与β0地中海贫血杂合子比较,前者有较高的血红蛋白和平均红细胞体积(MCV)水平。中间型组中84·6%(11/13)的病例至少携带一个βnt-28地中海贫血等位基因,而重型组只有20·3%(13/64)携带有该基因(P<0·0001)。在重型组中,与基因型为β0地中海贫血纯合子的病人相比,携带βnt-28地中海贫血基因双重杂合子病人的平均确诊时间和平均首次输血时间分别推迟3个月与5个月。结论βnt-28地中海贫血基因可以减轻β地中海贫血个体的临床表现和血液学改变,尽管如此,仍难于从基因型为βnt-28与β0地中海贫血基因双重杂合子来推断其表现型的严重程度,但βnt-28纯合子最有可能表现出较轻的临床症状。更多还原

【Abstract】 Objective To analyze the clinical and hematological features of Chinese with β~ nt-28-thalassemia mutations and determine whether it is possible to predict phenotypic severity from genetic factors.Methods 244 Chinese individuals with β-thalassemia were divided into β-thalassemia trait group(167 cases),intermedia group(13 cases) and major group(64 cases).Clinical and hematologic data were analyzed.β-thalassemia mutations,α-thalassemia genotypes and Xmn-I~Gγ promoter polymorphism at position-158 were determined.Results In β-thalassemia trait group,21 individuals were heterozygous for β~ nt-28 -thalassemia mutation and had higher hemoglobin level and MCV than those with heterozygous β~0-thalassemia mutation.In the intermedia group,the vast majority(11/13,84.6%) of patients carried at least one β~ nt-28 -thalassemia allele,whereas only 13/64 (20.3%) patients had β~ nt-28 -thalassemia mutations in the major group(P<0.000 1).In the β-thalassemia major group,inheritance of β~ nt-28 -thalassemia mutation might defer the mean age at diagnosis and age at first transfusion by 3 months and 5 months,respectively.Conclusion The presence of β~ nt-28 -thalassemia mutations in Chinese individuals may ameliorate the clinical and hematological condition.But it is difficult to precisely predict phenotypes from genotypes of patients that are compound heterozygous for β~ nt-28 and β~0 mutation.Patients with homozygotes for β~ nt-28 mutations could be predict to have moderate phenotypes.更多还原