昆明地区儿童地中海贫血筛查和基因诊断分析

Biochemical screening and genetic diagnosis of thalassemia in children from Kunming

摘要:

目的：调查云南省昆明地区儿童地中海贫血（地贫）基因突变类型和频率。方法对昆明地区1338例儿童进行RBC脆性、MCV、血红蛋白电泳生化筛查。对筛查阳性的α-地贫患儿用gap-PCR方法、β-地贫用PCR-RDB方法进行基因诊断。结果地贫生化筛查阳性率为11.36%(152 例)，基因诊断阳性率为8.59% (115 例)。115例经基因诊断确诊为地贫的样本中，α-地贫43例，β-地贫68例，α合并β地贫4例；43例α-地贫中，--SEA/αα型占47%，-α4.2 /αα型占21%，HbH病占14%；68例β-地贫共检测出6个基因位点发生突变，突变频率依次为βE（32%）、CD41-42（24%）、CD17（23%）、IVS-II654（10%）、CD71-72（10%）、-28（1%）。结论 昆明地区儿童地贫基因突变率较高，开展婚检及产检生化筛查和基因诊断十分必要。

Abstract:

OBJECTIVE: To investigate the types and frequency of gene mutations in children with thalassemia in Kunming, Yunan Province. METHODS: A biochemical screening for thalassemia was performed by testing RBC fragility, MCV and hemoglobin electrophoresis on 1338 children from Kunming, Yunnan Province. Genetic diagnosis was performed on the children with α-thalassemia by gap-PCR and on the children with β-thalassemia by PCR-RDB. RESULTS: The positive rate of the biochemical screening for thalassemia was 11.36% (152 cases). The positive rate of genetic diagnosis was 8.59% (115 cases). Of the 115 cases, α-thalassemia was found in 43 cases, β-thalassemia in 68 cases and α-combined-β thalassemia in 4 cases.--SEA/αα accounted for 47%, -α4.2/αα accounted for 21%, and HbH disease accounted for 14%. Six genotypes were found in 68 cases of β-thalassemia and the mutation frequency of βE was the highest (32%), followed by CD41-42 (24%), CD17 (23%), IVS-II654 (10%), CD71-72 (10%), and -28 (1%). CONCLUSIONS: The frequency of gene mutations for thalassemia is high in children from Kunming, Yunnan Province. Premarital and prenatal screenings and genetic diagnosis for thalassemia should be carried out in this area.