Single Base Substitution 에 기인한 유전병의 조기검진법 개발

Abstract

A method for detection of genetic diseases caused by point mutations was developed using FokI, one of the class-IIS restriction enzymes whose recognition site is separated from the cutting site. A special hairpin adapter containing both a double strand (ds) recognition domain and a single strand (ss) domain(s) was designed. FokI bound to the ds domain of such an adapter, but could not cleave the ss domain unless it was paired with a complementary region of the target ssDNA. By specifying the proper complementary sequence of the ss domain in the adapter, we could distinguish the mutant DNA from wild type DNA depending on the number of mismatches introduced at the cutting region. When one mismatch was introduced at the FokI cutting region, FokI could cut the mismatched dsDNA very efficiently regardless of the location of the mismatch on the cutting region. FokI cutting efficiency, however, decreased dramatically when two mismatches were introduced. Especially FokI did not cut the DNA when the two mismatches were more than one nucleotide apart on the FokI cutting region or three mismatches were introduced. This result can lend itself to development of convenient test kits or automation of the genetic disease screening procedure.