The load of genetic and partially genetic disorders in man. I. Congenital anomalies: estimates of detriment in terms of years of life lost and years of impaired life.

This paper represents an attempt to estimate quantitatively, the detriment associated with spontaneously arising congenital anomalies in man. The system used in the International Classification of Diseases (Chapter XIV, entries 740-759) has been followed to classify the congenital anomalies. Detriment was assessed using estimates of the years of life lost, years of life potentially impaired and years of life actually impaired, as indicators. The data on birth prevalences for the various conditions were derived from several epidemiological surveys carried out in Hungary and from the Hungarian Congenital Malformation Registry. Most of the information on mortality profiles was obtained from the records of the Hungarian Central Statistical Office, Budapest. An overall comparison of the prevalence figures in Hungary with those for the U.S. (this study aimed at complete ascertainment) and for the Canadian province of British Columbia (in this study, ascertainment is believed to be incomplete) showed that, in Hungary, at least certain classes of congenital anomalies, particularly some of the less severe ones, have been under-ascertained. Since detriment estimates are heavily dependent on accurate estimates of birth prevalences, we believe that the estimates of detriment arrived at using the Hungarian data may also be underestimates. In Hungary, the total birth prevalence of all isolated major congenital anomalies is of the order of about 600/10(4). Our calculations show that these congenital anomalies may cause, per 10(4) livebirths, about 4800 years of life loss, about 37000 years of potentially impaired life and about 4500 years of actually impaired life. In these calculations, it has been assumed that the average life-expectancy at live birth for the general population is 70 years. These estimates are considerably higher than those made by Carter for detriment associated with spontaneously arising monogenic disorders.