| Objective:Study the genetic epidemiology of thalassemia in Yunnan province. Ascertain the gene carrying rate of thalassemia in Yunnan province.Compare the result of hemoglobin electrophoresis screening in Native of Yunnan province and non-native of Yunnan province. Compare the results of hemoglobin electrophoresis screening in all kinds of nationalities and regions to infer the incidence of thalassemia. Discuss the cutoff value of hemoglobin electrophoresis screening for thalassemia in Yunnan province,provide more suitable cutoff value of hemoglobin electrophoresis screening for thalassemia in Yunnan province.Materials and methods:Analyse the 10181 outcomes of hemoglobin electrophoresis screening and select 340 outcomes who are analogue to the patients of thalassemia to make gene diagnoses.Combining with the blood screening and patients'native place and nationality, analyzing with Chi-square test and T test,to make sure whether there is significant difference among them.Use normal distribution and ROC curve to define the correlation and the best cutoff value of hemoglobin,especially Hb A2 and Hb F.Result:1. In 10181 cases of hemoglobin electrophoresis screening,6 kinds of a thalassemia which could be detected is 1.05% of the total population,18 kinds of (3 thalassemia which could be detected is 3.55% of the total population.It can be inferred that thalassemia which could be detected is 4.60% of the total population. This result may be a slight deviation of the actual situation.2. (1) In the crowd of no abnormal hemoglobin appers,the distribution of Hb A2's content is similar to normal distribution,the mean value is 2.82%,standard deviation is 0.411%.The distribution of Hb A2's content is similar to normal distribution in a thalassemia gene carriers,the mean value is 2.17%,standard deviation is 0.317%.The distribution of Hb A2's content is similar to normal distribution in (3 thalassemia gene carriers,the mean value is 5.30%,standard deviation is 0.898%.(2) There is no distinct regular pattern in the distribution of Hb F's content (3)There is no significant difference in Hb and MCH between a thalassemia gene carriers and normal population,however, there is significant difference in MCV between them.3. (1) In Yunnan province, the positive standard of hemoglobin electrophoresis screening for a thalassemia is recommended like:Hb CS appears,or Hb Bart's appears, or Hb H appears, or Hb A2<2.8%. (2) For higher sensitivity,the positive standard of hemoglobin electrophoresis screening for (3 thalassemia is recommended like:Hb A2 >3.5%,or Hb F>2.0%,or Hb E appears.For higher specificity,the positive standard of hemoglobin electrophoresis screening forβthalassemia is recommended like:Hb A2>4.5%,or Hb E appears. (3) Before the gene mutations which lead Hb D,Hb J, Hb Hope or Hb S could be detected,we suggest that don't care about it.4.18 in 91 cases of a thalassemia phenotype positive were detected a thalassemia gene,degree of conformity is 19.8%.81 in 174 cases ofβthalassemia phenotype positive were detectedβthalassemia gene,degree of conformity is 46.6%.Conclusions:1. Yunnan province is a high-prone areas of thalassemia, it is necessary to develop widely prenatal screening and pre-pregnancy screening,to achieve the the purpose that improvement of population quality and preventing birth defects. 2. The incidence of thalassemia is provided with distinct difference in different regions and nations, each region should determine the cutoff value for screening whith depending on local conditions.3.Connecting genetic diagnosis,hemoglobin electrophoresis screening and blood screening are more useful toβthalassemia than a thalassemia.
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