分子生物学分子生物学 (29).pdf

Chapter 12 Gene Diagnosis 12.1 Concept,Features and Strategies of Gene DiagnosisIn 1976,the Chinese American scientist,Kan YW,comingfrom the university of California,first used DNA molecularhybridization technology to diagnose-thalassemia in theworld.Yuet Wai KanGene diagnosis is to diagnose human bodystate and diseases via detecting genes andgene expression products by usingmolecular biology techniques.12.1.1 Concept of Gene DiagnosisThe target molecules of gene diagnosisinclude DNA,RNA or protein.The detected genes can be endogenous,i.e.human genes,or exogenousfrom virusesand bacteria.12.1.2 Features of Gene DiagnosisHigh specificityHigh sensitivityEarly diagnosisExtensive application12.1.3 Strategies of Gene DiagnosisSelect different diagnosis strategies according to how much the disease-causing or related genes are known.Direct diagnostic approach,directly ditect molecular structures and expression of pathogenic genes.Indirect diagnostic approachuse polymorphic genetic markers for linkage analysis with disease-causing genes.(1)Direct diagnostic approachNecessary Applied SituationsThe mutations of the detected gene has a direct causal relationship with the onset of the disease.The normal molecular structure of the detected gene has been identifed.The mechanisms from the gene alteration to disease are well known.(2)Indirect diagnosis approachNecessary Applied SituationsThe pathogenic gene is unknown or the gene sequence has not been decoded.The gene mutation site is unclear.Inconvenient detection of the gene pathogenic site.Indirect diagnosis is to detect geneticmarkers associated with pathogenic genes.Thank you!