Quality assessment in cytogenetic and molecular genetic testing: the experience of the Italian Project on Standardization and Quality Assurance

The first Italian national trial of external quality assessment in genetic testing was organised within the framework of the " Italian National Project for Standardisation and Quality Assurance of Genetic Tests". Sixty-eight Public Health Service laboratories volunteered for the trial, which involved molecular genetic tests (cystic fibrosis, β-thalassaemia, familial adenomatous polyposis coli and fragile-X syndrome) and cytogenetic tests (prenatal and postnatal, the latter included cancer cytogenetics). The response rate was high (88.2%). The level of analytical accuracy was good, i.e., the percentage of laboratories that correctly genotyped all samples was 89.3% for cystic fibrosis, 90.9% for β-thalassaemia, 100% for familial adenomatous polyposis coli (despite two laboratories did not complete the analysis because the amount of DNA was considered insufficient), and 90.5% for fragile-X syndrome. Written reports differed widely and were judged "inadequate" in over 50% of cases. Most la...