An appraisal of the application of recombinant DNA techniques to chromosome defects

Until the first gene was cloned over 10 years ago, strategies designed to gain insight into human disease relied on the isolation and characterization of gene products. The scientist could only speculate about the molecular basis of a given phenotype. If the biochemical defect is not known, as is still the case for many chromosomal disorders, the task of understanding the disease process is an even more formidable one.