Autosomal dominant polycystic kidney disease types 1 and 2: Assessment of US sensitivity for diagnosis

PURPOSE: To estimate the sensitivity and specificity of ultrasonography (US ) in the diagnosis of autosomal dominant polycystic kidney disease (ADPKD) types 1 and 2, as compared with those of genetic linkage analysis. MATERIALS AND METHODS: A renal US and DNA analysis for ADPKD was performed in 319 patients who were at risk, 161 of whom were younger than 30 years, f rom 54 families with ADPKD. The sensitivity of US for diagnosis was estimat ed by comparing the US results with genotypes inferred from linkage studies . RESULTS: The sensitivity of US in individuals younger than 30 years who wer e at risk was 95% for ADPKD type 1 but only 67% for ADPKD type 2. The sensi tivity of US for either ADPKD type 1 or ADPKD type 2 in individuals aged 30 years or alder who were at risk was 100%. The overall sensitivity in indiv iduals younger than 30 years was 93%. For both ADPKD types 1 and 2 in all p atients, US demonstrated a sensitivity of 97%, a specificity of 100%, and a n accuracy of 98%. CONCLUSION: US is the first-line imaging technique that should be used in t he diagnosis of ADPKD. The sensitivity in individuals aged 30 years or olde r is 100%, but if there is a clinical suspicion of ADPKD type 2 in individu als younger than 30 years, linkage analysis should also be considered.