Prenatal diagnosis of inherited diseases: 20 years' experience of an Italian Regional Reference Centre

Background: The demand for molecular prenatal diagnosis (PD) of inherited diseases to help high-risk couples make informed reproductive decisions has increased in the past decade. Methods: We provided multidisciplinary pre-test counselling to 1248 couples at high risk of having a child affected by an inherited disease. Results: After multidisciplinary counselling, 1171 couples requested PD for one of 73 inherited diseases. Of these, 995 (85.0%) were performed on DNA from chorionic villi (CV) and 176 (15.0%) on samples from amniocentesis. The occurrence of pregnancy loss (0.6%) and major complications did not differ significantly between the two groups. We made a diagnosis in all cases (including 8 twin pregnancies) except in 4/995 cases of CV sampling (0.4%) and in 3/176 of amniocentesis (1.7%) due to insufficient DNA. In 15 cases, molecular analysis revealed non-paternity. Conclusions: PD by analysis of foetal DNA from CV is a reliable aid in reproduction decision-making for couples at high risk of inherited diseases. The complexity of experimental procedures and the specific expertise required for the pre- and post-test multidisciplinary counselling suggest that PD be performed in reference centres also within the framework of supranational networks.