Current status of DNA diagnosis for hereditary nephropathies.

The molecular genetic defect of many hereditary nephropathies has been assigned to a specific chromosomal region or has even been identified. While the localization of a gene permits an indirect genotype analysis to estimate the risk status of a close relative of a patient with a proven clinical diagnosis, it is not possible to confirm a diagnosis in case of inconclusive clinical data. In some nephropathies, the gene has been cloned and mutations identified. By demonstrating the molecular genetic defect in these patients, the diagnosis can be ensured and an easily assessible method of carrier detection can be offered. The possibilities and limitations of DNA diagnosis in some important nephropathies are outlined.