[Incidence and prevalence of genetically-determined disorders in The Netherlands; a literature study]

To analyse if data now available on frequencies of genetic disorders are sufficient to be used in future as indicators when an evaluation of new developments is desired for policy-making purposes.

Literature study.

The Netherlands.

Using automated literature search systems, papers published before October 1991 were surveyed and an inventory of incidence and prevalence of genetic disorders in the Netherlands was made.

Depending on the pattern of heredity differences in available data and their validity were found. Valid data on most of the II congenital anomalies investigated were available from the EUROCAT registration in the northern Netherlands. This method of data collecting is also suitable for the evaluation of prevalence development. On the 29 multifactorial diseases occurring later in life that were investigated many data were available, although the varying sources made comparison difficult. These data were often out of date and had a highly varying validity. Of 3 chromosomal abnormalities the prevalence at birth was known. Of only 22 out of 650 monogenic disorders, described in the Netherlands up to 1991, the prevalence at birth and(or) in the population was known.

Data on frequency of genetic disorders can be collected but the information now available is insufficient to serve as an indicator for government policy. Frequencies should also be considered in relation to the impact of the disease on the individual, his environment and society.