[Positional cloning--current status and future directions].

Abstract

Several strategies for isolating disease genes have been developed. In functional cloning, the gene is isolated based on information on the function of gene products (proteins). In contrast, positional cloning is based on the isolation of the disease gene, starting from the knowledge of its location on the genome. The flow chart of positional cloning was described as follows; 1) identification of the location of the disease gene by linkage analysis. 2) construction of the physical map spanning the region. 3) isolation of the candidate genes from the region. 4) identification of mutations in the candidate genes, which is specific to the disease. The current concept and strategies on the positional cloning is discussed.