Polycystic kidney disease (PKD) Dr Trisha Macnair Dr Rob Hicks In PKD, fluid-filled cysts develop in the kidneys. It's one of the most common inherited disorders and the fourth commonest cause of kidney failure.

In this article

What causes it? What are the symptoms?

How is it diagnosed? What's the treatment?

Advice and support

There are two types of inherited PKD. The more common type is autosomal dominant PKD, which usually causes symptoms in midlife, although it may become apparent much sooner.

Ninety per cent of cases are autosomal dominant due to an abnormal gene on chromosome 16. It needs only one parent to pass on the abnormal gene, giving a person a one-in-two chance of developing the disease later in life.

The childhood form, autosomal recessive PKD, is much rarer. It affects about one in 10,000 babies. In at least some cases, the gene is found on chromosome 6.

It needs both parents to pass on an abnormal gene - meaning a child has a one in four chance of developing the disease in childhood. It progresses rapidly.

PKD may also occur as a non-inherited, acquired form as a result of long-term kidney problems, dialysis and old age.

The gene responsible for causing polycystic kidney disease has been identified. This means those with a family history of the disease can receive genetic counselling to help with family planning.

In PKD, fluid-filled cysts develop in the kidneys, giving them a honeycomb appearance. Gradually these cysts replace the normal kidney tissue, enlarging the kidneys but making them less and less able to function normally. Eventually, the kidneys fail completely.

In addition to the kidney damage, the fluid in the cysts may become infected, which can cause pain in the back and abdomen, and trigger fever.

Adults may not develop symptoms for many years. When they do arise they may include:

• Blood in the urine
• Vague discomfort or aching in the abdomen and/or lower back
• Attacks of sudden and severe pain in the abdomen and/or lower back
• Headaches
• Urinary tract infections

Adults can also develop cysts in the liver and pancreas, abnormal heart valves, kidney stones, brain aneurysms (bulges in the walls of blood vessels) and diverticulosis (small bulges in the wall of the colon).

High blood pressure (hypertension) may develop as a result of kidney damage. This may exacerbate the problem by damaging the kidneys further. However, progress of the disease is usually very slow and it may go undetected for years.

Babies with PKD are usually identified soon after birth because the enlarged kidneys cause the abdomen to be very swollen. Other organs such as the liver may be involved and, although severity varies, some babies die soon after birth.

If there's a family history of the disease, an ultrasound scan during pregnancy may detect the disease before the baby is born.

Adult PKD may be discovered by chance when someone is undergoing tests for a separate problem. If there's a family history, it may be discovered when members of the family are routinely screened.

It's possible to screen for the autosomal dominant PKD gene using DNA analysis on blood tests or CVS sampling during pregnancy.

At present, it isn't possible to prevent the cysts forming within the kidneys. However, it is possible to slow the damage.

Keeping blood pressure at a safe level helps prevent further damage to the kidneys. If infection develops, it needs to be treated promptly and effectively.

Eventually, kidney failure occurs. For around seven out of ten people with adult PKD, this happens by the age of 65. At this stage, kidney dialysis or transplant is necessary.

PKD Charity

Tel: 01388 665004
Email: support@pkdcharity.org.uk
Website: www.pkdcharity.co.uk

This article was last medically reviewed by Dr Rob Hicks in July 2006.