Objective To analyze the causes of blood transfusion adverse reactions in children,and to explore the measures to reduce the adverse reactions of blood transfusion in children.Methods Collect 30 518 cases of transfusion reaction data which is during 2009 to 2014 in Kunming Children's hospital for analyzing.Results 166 cases of transfusion reaction occurred and the occurrence rate is 0.54％ in 30 518 cases,allergic transfusion reaction accounted for 89.16％ (148/166),non-hemolytic febrile reaction 10.24 ％ (17/166),hemoglobinuria accounted for 0.60 ％ (1/166);In children the transfusion reaction rate of hemapheresis platelet is 1.92％(72/3 743),plasma is 0.43％(56/13 132),suspension red blood cells is 0.28％(38/13 480);the signs and symptoms of children's blood transfusion reaction:simplex urticaria and rash 74.10％(123/166),simplex fever 10.24％ (17/166),rash associated with fever 5.42％ (9/166),eyelid or oral edema (mild angioneurotic oedema) 9.04％ (15/166),,Bronchospasm (mild) 0.60％ (1/166),simple hemoglobinuria 0.60％ (1/166).Conclusion Children with blood transfusion adverse reactions to allergies,mainly for local or systemic rash;Platelet is the most-common blood component that causes transfusion reaction with children.

Recently,a fast developing new technology for gene modification named as CRISPR-Cas9 which based on CRISPR-Cas9 system composed of clustered regulatory interspaced short palindromic repeat(CRISPR) and Cas9 nuclease(CRISPR associated system 9,Cas9)has been developed. CRISPR-Cas9 system is a kind of immune mechanism widely found in bacteria and archaea. This mechanism can help bacteria and archaea against exogenous DNA by the approach of specifically breaking DNA. Later,this mechanism was found to be useful for gene modification and gene deletion. At present,this technology has been applied to gene modification and therapy. Many studies have shown that the technology,compared with other genetic technology,has higher efficiency and accuracy,and it has promoted genetic engineering progress. Summarized here is the principle and application advance of CRISPR-Cas9.