ADPKD affects approximately 1 in 800 of the general population. It is inherited in an autosomal dominant manner due to mutations in one of three genes.
There are a number of potential presenting features:
- Renal Failure
- Unexplained hypertension
- Recurrent loin pain
- Recurrent UTIs
- Enlarged kidneys
- Incidental finding of renal, liver or pancreatic cysts on USS
- Subarachnoid Haemorrhage
- Family history of ADPKD
This is mainly a disease of adults.There are a small number of affected individuals who will present in childhood, and when this is the case there may be confusion between ADPKD and the normally more severe recessive form of the disease. The family history will usually allow differentiation between the two forms of the disease.
The most common presentation in general practice is likely to be individuals who are at risk of ADPKD by reason of their family history. The offspring of affected patients are at 50% risk of themselves being affected. Parents and siblings of affected individuals may also be at risk.
Diagnostic difficulty can arise because this is an age dependant disease. Mutation analysis of the associated genes is not routinely available. Assessment of whether an ‘at risk’ family member is affected is therefore based on renal imaging. Currently this is normally done by ultrasound scanning. A normal abdominal ultrasound scan at age 30 yrs in an ‘at risk’ individual is associated with a residual risk of approximately 2%.
A proportion of patients with ADPKD will present with a subarachnoid haemmorhage (SAH) before renal abnormalities are obvious. This should always be considered where there is a family history of SAH with or without renal cysts/renal failure. Approximately 8% of individuals with autosomal dominant polycystic kidney disease (ADPKD) have berry aneurysms.
There are some families with ADPKD where SAH seems to be a more common feature of the condition, and in these families the risk of berry aneurysm in those with ADPKD can be as high as 25%. Families with ADPKD, and a family history of SAH or stroke, are likely to be screened for berry aneurysm. However, if there is no family history, it is extremely unlikely that they would be screened for aneurysms.
The genetics service has established a clinic specifically for the management of patients with familial renal disease. Referral should be considered for patients presenting with cystic renal disease, or those who may be at risk of this.
