Mapping Inherited Diseases by Linkage Analysis

Family studies have provided experimental observations enabling geneticists to recognize many human genetic traits and diseases. Single-gene Mendelian traits are usually deduced by straightforward inspection of the data, but sophisticated statistical methods have had to be developed to analyze phenotypes that have more complex modes of inheritance. An ongoing catalog of these traits has been compiled by Victor McKusick for over 30 years; 4344 traits are listed in the eighth edition (1988) of Mendelian Inheritance in Man (1 ). The exponential increase in reporting of new human genetic information has led to this data base being computerized, and it is available in daily updated form for geneticists to interrogate via academic networks.