Recent advances in the molecular analysis of inherited disease

Many important human genes have been cloned during the last ten years. In some cases, using reverse genetic techniques [Orkin, S. H. (1986) Cell 47, 845–850], disease‐causing genes have been isolated whose product was previously unknown. Important examples include the dystrophin protein which, when mutated, gives rise to either Duchenne or Becker muscular dystrophy [Koenig, M., Hoffman, E. P., Bertelson, C. J., Monaco, A. P., Feener, C. and Kunkel, L. M. (1987) Cell 50, 509–517; Monaco, A. P., Bertelson, C. J., Liechti‐Gallati, S. & Kunkel, L. M. (1988) Genomics 2, 90–95; Koenig, M., Monaco, A. P. & Kunkel, L. M. (1988) Cell 53, 219–228] and the cystic fibrosis transmembrane conductance regulator (CFTR) [Riordan, J. R., Rommens, J. M., Kerem, B.‐S., Alon, N., Rozmahel, R., Grzelczak, Z., Zielenski, J., Lok, S., Plavsic, N., Chou, J.‐L., Drumm, M. L., Ianuzzi, M. C., Collins, F. S. & Tsui, L.‐C. (1989) Science 245, 1066–1073]. Recently the technology for systematically detecting single base‐pair changes by chemical methods, enzymatic methods or direct DNA sequencing has greatly expanded and simplified. In addition to providing structural information about these clinicall