Sixteen years' experience of counselling, diagnosis, and prenatal detection in one genetic centre: progress, results, and problems.

The work of one Genetic Centre over 16 years, covering about 14 000 kinships, is described. The numbers registered in a year increased from an average of 477 in the early 1960s to 1612 in 1976/1977. The increase is largely, but not entirely, attributable to the advent of prenatal diagnosis, and an account is given of our experience with this. In 1916 patients who had a successful amniocentesis, results indicative of fetal abnormality were found in 4.3% and a balanced translocation was found in an additional 0.9%. Results indicative of fetal abnormality were found in 3.5% of mothers referred because of a maternal age of 40 or more, 3.9% referred because of a high risk of neural tube defect, and 19.3% referred because of a high risk of an inborn error of metabolism. A number of cases with difficult diagnostic problems are described.