Describe the general strategy to map disease causing genes and main experiments in the Rommens et al paper (Identification of the cystic fibrosis gene: chromosome walking and jumping Science, 1989).

The Cystic Fibrosis gene is the first disease gene identified through positional cloning in 1989. Describe the general strategy to map disease causing genes and main experiments in the Rommens et al paper (Identification of the cystic fibrosis gene: chromosome walking and jumping Science, 1989). The essay should contain a good description of traditional strategies and current ones , ideally with graphs/figures to illustrate them.