Family Study of Early Hypertension in Children and Young People at Risk of Autosomal Dominant Polycystic Kidney Disease

INTRODUCTION Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the commonest genetic cause of chronic kidney disease. Despite being inherited, most people do not get symptoms until adulthood with mean age of chronic renal failure around 53 years. Hence, it was thought that there is no need to screen children and young people (C&YP) at risk of ADPKD until old enough to understand and agree to testing. Linked to this, imaging criteria to diagnose ADPKD mostly cover adult ages.

The validity of this 'adults only' approach is challenged by reports of hypertension in C&YP with ADPKD, affecting up to a quarter by late teens. This is important in deciding whether to change screening policy because early treatment has the potential to reduce risk of cardiovascular events long-term. Death from cardiovascular disease is still a frequent event in ADPKD families, even before reaching end-stage kidney disease. Not only does the renal damage in ADPKD affect BP and cardiovascular health but there is evidence that ADPKD causes generalised endothelial dysfunction. This provides further justification for good BP control and treatment from the earliest stages of ADPKD.

Currently, it is not known whether the estimated prevalence of hypertension in C&YP with ADPKD is overestimated because most evidence comes from specialist Paediatric Nephrology centres, where it would be expected that the more severe cases would be managed. This study will determine whether blood pressure (BP) should be screened in all C&YP at risk, as well as testing the utility of ultrasound and genetic approaches.

This proposed study will be most comprehensive assessment of blood pressure in ADPKD across all age groups. As a result, information gained may revolutionise the approach to the measurement and management of BP in medical practice, particularly in children.

PATIENT AND PUBLIC INVOLVEMENT This study has been set up to specifically consider individuals with ADPKD and so the investigators have designed this study in discussion with The PKD Charity. The investigators will continue to utilise this wealth of patient experience as this study is conducted by keeping the PKD Charity informed of progress, presenting results at patient group meetings and conferences, so that patients are able to see the work that the investigators are doing to improve their understanding of ADPKD. Any publications resulting from this work will be sent to the PKD Charity for inclusion on their website.