What is EAST syndrome?
EAST syndrome is a very rare condition that affects the kidneys and other organs in the body. EAST stands for:
Epilepsy (fits or seizures)
Ataxia (coordination difficulties)
Sensorineural deafness (a form of hearing impairment)
Tubulopathy (a kidney problem that affects salt levels in the body).
EAST syndrome is extremely rare. It is believed to affect fewer than 1 in 1,000,000 people in the UK. By 2016, only 26 people with EAST syndrome had been identified.
It is usually diagnosed in childhood and is equally common in females and males.
EAST syndrome was only identified in 2009 so research and treatment are still in the early stages of development. It is similar to Gitelman syndrome or Bartter type 3 syndrome but in EAST, there are the added features of epilepsy, ataxia and deafness.
EAST syndrome is also sometimes called SeSAME syndrome (seizures, sensorineural deafness, ataxia, intellectual disability and electrolyte imbalance). Some research suggests that any perceived intellectual disability is really a result of coordination and/or hearing difficulties.
What are the signs and symptoms of EAST syndrome?
The range and severity of symptoms can vary in people with EAST syndrome, even within the same family (it can run in families, which is explained below).
Seizures usually start before the age of one.
Coordination difficulties tend to be noticed in early childhood due to delayed development, and wobbly or weak movement.
Hearing impairment is present from birth and varies from mild to severe. It does not appear to get worse and may improve with treatment.
What causes EAST syndrome?
EAST syndrome is caused by changes in a gene called KCNJ10, which is important for the normal development of the brain, hearing and kidneys. In particular, this gene affects part of the kidney called the distal convoluted tubule, which is responsible for filtering the blood and reabsorbing nutrients such as salt and potassium. When the gene does not work properly, salt and potassium are lost in the urine instead of being reabsorbed into the blood.
How is EAST syndrome diagnosed?
EAST syndrome is diagnosed when all of the key symptoms (epilepsy, ataxia, sensorineural deafness and tubulopathy) are present. Blood tests will also often show low levels of potassium and magnesium and high levels of bicarbonate plasma. This is known as hypokalaemic alkalosis.
The diagnosis can also be confirmed by genetic testing.
Does EAST syndrome affect other parts of the body?
As well as affecting the kidneys, EAST syndrome also affects:
- the brain, causing fits or seizures
- muscles, causing weak and wobbly movements
- the ears, causing hearing difficulties
Does EAST syndrome run in families?
EAST syndrome is a genetic condition. It is caused by an abnormality or mutation in a gene called KCNJ10.
Everybody has two copies of the KCNJ10 gene, one from each parent.
Healthy people have two normal copies.
Carriers have one copy that works normally and one that doesn’t. Carriers are usually healthy because the normal copy can still do its job. However, they can still pass EAST syndrome on to their child.
In people with EAST syndrome, neither copy of the gene works properly.
When both parents are carriers, a child could be healthy with two normal genes; a healthy carrier like their parents, with one healthy and one faulty gene; or affected, with both genes being faulty. This pattern is called autosomal recessive inheritance.
How is EAST syndrome treated?
There is currently no specific treatment for EAST syndrome, so the focus is on managing the key symptoms. As well as kidney doctors, other medical specialists are likely to be involved in a person’s care due to the variety of symptoms, so it is important that care is properly coordinated.
- Anti-epileptic medication can be prescribed to treat seizures, under the care of a neurologist – a doctor who treats diseases of the brain and nerves.
- Physiotherapy may be used to help with movement coordination and physical development.
- Hearing aids can help with deafness under the care of an audiologist.
- Dietary changes and potassium and magnesium supplements are usually recommended for kidney care.
Lifelong monitoring and treatment are needed. The amount of medication and supplements required are likely to change over time.
Where can I get more information or support about EAST syndrome?
We are not aware of any UK-based support groups for EAST syndrome. If you know of any EAST syndrome patient groups, please let us know so we can share their details.
Publication date: 11/2023
Review date: 11/2026
This resource was produced according to PIF TICK standards. PIF TICK is the UK’s only assessed quality mark for print and online health and care information. Kidney Care UK is PIF TICK accredited.