This is a rare and inherited condition. Primarily, it is characterized by severe high blood pressure (it is also known as hypertension) and it often develops at an early age. At the start, Liddle’s syndrome might not be related to signs and symptoms, but untreated hypertension can eventually cause stroke or heart condition. Also, affected people may have low levels of potassium in the blood (known as hypokalemia) and metabolic alkalosis.
Liddle’s syndrome is generated by changes that are happening in the SCNN1G or SCNN1B genes or it is inherited in an autosomal dominant manner. The therapy of Liddle’s syndrome combines a low sodium diet and potassium-sparing diuretics to reduce blood pressure and normalize potassium levels. It is noticed that conventional antihypertensive therapies are not effective. Liddle’s syndrome is a rare condition. But, the prevalence is not known. This type of disease has been found in populations all around the world.
Liddle’s syndrome is inherited in an autosomal dominant pattern. This is meaning that one copy of this altered gene in each cell is sufficient to cause the disorder. A person who suffers from Liddle’s syndrome has a 50% chance with each pregnancy to pass the altered gene to his or her child. Often, the examination of Liddle’s syndrome is imagined to establish the presence of early-onset hypertension (this is known as high blood pressure), especially in people who have a family history of this condition.
Symptoms:
Primarily, Liddle’s syndrome is characterized by severe and early-onset hypertension. This condition may not be associated with any signs and symptoms initially, but untreated high blood pressure can lead to stroke and heart disease. Also, affected people can have hypokalemia (which is low blood potassium) and metabolic alkalosis. Some of the most common symptoms of hypokalemia include heart palpitations, constipation, muscle pain (myalgia), fatigue, and weakness.
In most cases, Liddle’s syndrome becomes apparent at a young age. But, some people who are affected with Liddle’s syndrome are not diagnosed until they are well into adulthood. The most common symptoms of Liddle’s syndrome include hypokalemia, hypertension, constipation, and arrhythmia. For most people, symptoms of Liddle’s syndrome will vary from one person to another.
Not all people with Liddle’s syndrome will have all of the listed symptoms. This is seen in many studies which are done in people who suffer from Liddle’s syndrome. The information is collected from all people and they have concluded about the previously mentioned symptoms.
Causes:
Liddle’s syndrome is caused by mutations that are happening in the SCNN1B or SCNN1G gene. These genes provide instructions for creating a bit of protein complex, which is understood as ENaC (epithelial sodium channel). These channels are found in the epithelial cells, at the surface of these cells, which are seen in many tissues of the body, such as kidneys, where the channels transport sodium into cells. In kidneys, ENaC carries free feedback to signals which sodium levels in the blood are too low and this allows the sodium to flow into the cells.
From the kidney cells, the sodium is returned to the bloodstream (this is a process which is called reabsorption) rather than being removed from the body in the urine. Mutations that are happening in the SCNN1B or SCNN1G gene change the structure of the respective ENaC subunit. These changes alter a region of the subunit which is involved in signaling for its breakdown (known as degradation) when it is no longer needed.
As a result of these mutations, the subunit proteins are not degraded and more ENaC channels remain at the cell surface. The boost in the carriers at the cell surface abnormally increases the reabsorption of sodium (which is followed by water) and this leads to hypertension. The reabsorption of the sodium inside the blood is linked with the removal of potassium from the blood, so the excess sodium reabsorption leads to hypokalemia.
