Epidemiological estimates of autosomal dominant polycystic kidney disease (ADPKD) diagnosed cases in Malta

Abstract

Background/Objectives: Estimating the prevalence and inci- dence rates of ADPKD is challenging due to the highly variable expression of the disease. Here we investigate the epidemiology among ADPKD diagnosed cases in an isolated small island of Malta. Methods: A total of 59 unrelated cases (38 males, 21 females) over 18 years with clinical features of ADPKD were studied. A detailed three-generation pedigree was generated where possible. Results: The estimated point prevalence of ADPKD for the Maltese adult population was 2.1 (95% CI 1.7–2.5) per 10,000 inhabitants and the estimated annual incidence rate of ADPKD was 1.6 per 100,000 person-years (95% CI 0.78–3.1). The annual incidence rate of ESRD in ADPKD patients was 0.78 (95% CI 0.21–1.98) per 100,000 person-years with a male-to-female ratio of 2.8:1. Moreover the crude percentage of clinically diagnosed ADPKD adult patients on renal replacement therapy (RRT) was 9.6%. Data on the Maltese population was retrieved from the National Statistics Office (NSO). Conclusion: Labelled as a rare disease, ADPKD is an under- estimated cause of ESRD. The high percentage of patients on RRT stimulates the need of further studies to delay ESRD. Moreover, this study highlights the need of genetic testing in order to con- firm the genetic cause of renal cysts.