Medullary cystic kidney disease (MCKD) is an inherited condition. It belongs to a group of diseases known as cystic kidney disease. Genetic changes cause abnormal blisters of fluid (cysts) to grow in the kidneys.
The cysts develop in the inner part (medulla) of the kidney. Scar tissue forms and the kidneys shrink as the outer section (cortex) thins. The kidneys lose their ability to remove enough fluid from filtered wastes and pass great amounts of undiluted urine. There is no cure. This condition often causes kidney failure in people between 20 and 50 years of age.
Symptoms of MCKD
Symptoms usually begin before the age of 20, but they vary greatly. A few people do not have any symptoms until much later in life.
Symptoms may include:
- excessive urination, caused by the reduced ability of the diseased kidneys to respond to antidiuretic (fluid-holding) hormones
- getting up in the night to urinate
- low blood pressure
- unexplained weight loss
- generally feeling unwell
- nausea and vomiting
- skin changes, such as pale or yellowish skin tones and easy bruising
- muscle cramps or twitches
- retarded growth in children.
Complications of MCKD
Some of the complications associated with MCKD include:
- ulcers and bleeding of the gastrointestinal tract
- loss of bone density and increased risk of fractures
- end-stage kidney disease
- high blood pressure (caused by the failing kidneys)
- heart problems, including pericarditis or congestive heart failure.
Pattern of inheritance of MCKD
MCKD is an inherited disease transmitted in an 'autosomal dominant' pattern, which means that the condition will occur even if the genetic changes are inherited from only one parent. The condition can occasionally occur when there is no family history of the disease.
The childhood disease 'juvenile nephronophthisis' is similar to MCKD, but usually occurs in young children and is due to an inherited recessive genetic condition. This means that the child must receive the genetic changes from both parents in order to develop the condition.
Diagnosis of MCKD
Tests to diagnose MCKD may include:
- blood tests – to check sodium levels, kidney function and red blood cell count
- urine tests – to check the concentration of urine
- x-rays – to check the size of the kidneys
- ultrasound – to look for cysts
- computed tomography (CT) scan – to look for cysts, if other tests are not clear or if more information is needed
- renal biopsy – a small piece of kidney tissue is surgically removed and sent to a laboratory for analysis
- genetic testing – to confirm the presence of genetic changes.
Treatment for MCKD
Medullary cystic kidney disease is a slow, progressive disease. There is no cure. Treatment aims to manage the symptoms and decrease the risk of complications, which include:
- dietary changes – drinking large volumes of fluid and adding salt (sodium) to the diet will help make up for the vast amounts of fluid and salt lost through excessive urination. Once kidney failure occurs, treatment may include eliminating foods that contain phosphorous and potassium
- avoiding dehydration – your doctor may recommend avoiding activities that could lead to dehydration, such as vigorous sport or staying outside on a hot day
- growth hormone – children with MCKD may need growth hormone treatment.
Everyone with MCKD will eventually need treatment for kidney failure. Treatment options include:
- medication – to manage symptoms such as high blood pressure, anaemia or gout
- kidney transplantation
- conservative care.
Where to get help
- Your doctor
- Kidney Health Australia Information Service Tel. 1800 454 363
Things to remember
- MCKD is an inherited condition that causes the growth of abnormal blisters of fluid (cysts) in the kidneys.
- MCKD often causes kidney failure in people between 20 and 50 years of age.
- There is no cure – treatment aims to manage the symptoms and reduce the risk of complications.
This page has been produced in consultation with and approved by:
Kidney Health Australia
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