In the information age, information is usually communicated and exchanged with heterogeneous databases in a distributed internetworking environment. When multiple heterogeneous databases show different values for the same data item, its actual value is not known with certainty. Probabilistic relational databases have extended from the relational database model by incorporating probability measures to capture the data uncertainty associated with data items. In this paper, we apply the probabilistic relational database techniques to the area of biomedical informatics. We address the issue of database interoperability by using a data warehousing approach to resolve mismatched domains and to integrate information from different data sources. We then develop query processing strategies to effectively evaluate and answer queries from the consolidated database.