The results of our research programme in the field of renal and systemic diseases included in the monographs of the international publishers, recognized scientific journals and presented at the numerous international scientific meetings and congresses as well as the awarded organization of the 19th European Congress of Pathology, held in Ljubljana in September 2003 contributed to the worldwide recognition of Slovenia and enhanced our international collaboration and exchange. In our country, they contributed to the common progress of medical science, increase of the quality of health service and education programme, introduction of new modern technologies and training of young scientists. The results of our research of the head and neck tumours will improve early detection of precancerosis and carcinoma in the head and neck region, and will enable to choose more appropriate treatment. Several publications in international scientific journals and in a monograph of the WHO, as well as invited lectures at international scientific meetings represent an important promotion of Slovenia and its researchers. We developed an efficient molecular genetic approach for identification of families with hereditary non-polyposis colorectal cancer (HNPCC syndrome) based on detection of microsatellite instability in tumors and genetic analysis of mismatch repair genes. This approach enables to perform a population screening and identification of novel families with this syndrome, early detection and treatment of the disease. With molecular genetic analysis of RET oncogene in patients with familial form of medullary thyroid cancer we confirmed already known and detected new families with multiple endocrine neoplasia MEN2. We performed genetic analyses in families with other hereditary diseases including Alport syndrome, benign familial hematuria, hereditary infertility in man, Darier disease and Stargardt disease. We found several new and for Slovenian population specific mutations. We have optimized DHPLC methodology for mutation detection in CFTR gene and have found out the correlation of MFOLD-predicted DNA secondary structures with separation patterns obtained by capillary electrophoresis- SSCP analysis. We have constructed first DNA genotyping microarray (gene chip) for the ABCR gene associated with retinal degeneration.