High Quality Content by WIKIPEDIA articles! The Leiden Open Variation Database (LOVD) is a free, flexible web-based open source database to collect and display variants in the DNA sequence. The focus of an LOVD is usually the combination between a gene and a genetic (heritable) disease. All sequence variants found in individuals are collected in the database, together with information about whether they could be causally connected to the disease (i.e. a disease-causing variant or mutation) or not (i.e. a non-disease causing variant). Specialized doctors (clinical geneticists) use LOVDs to diagnose and advise patients carrying a genetic disease. Ideally, if a patient has been screened for mutations and one has been found, information in LOVD can predict the progress of the disease.