Mass screening and genetic counseling in mendelian disorders

The purposes of this paper are to examine the possibilities for additional mass screening and genetic counselling programs for mendelian carrier states and disorders, and to pose at least some of the questions raised by these possible programs. In the discussion it is assumed that future decisions regarding which programs are actually begun, and when, will result from consideration of the following factors: the frequency of the carrier state disease; the burden imposed on physical and psychologic health by the disease; the degree to which the screening and counseling program is perceived as offering a helpful alternative to those at risk; the availability of accurate, relatively simple and inexpensive methods for identifying the carrier state or disease, and the availability of adequate genetic counseling as an integral part of the program. While ideally these factors may ultimately be evaluated in more precise, quantitative terms, the present state of knowledge in medical genetics forces one to rely on subjective judgements. It can be estimated that serious mendelian diseases affect a total of over 1% or at the most about 2%, of the general population.