Info
Liddle’s syndrome
Liddle syndrome is an inherited form of high blood pressure (hypertension).
- caused by mutations in the SCNN1B or SCNN1G gene.
- Each of these genes provides instructions for making a piece (subunit) of a protein complex called the epithelial sodium channel - ENaC.
- These channels are found at the surface of certain cells called epithelial cells in many tissues of the body, including the kidneys, where the channels transport sodium into cells.
- TLDR: 做不出 ENaC，所以不能排鈉
- Mutations in the SCNN1B or SCNN1G gene change the structure of the respective ENaC subunit.
- The changes alter a region of the subunit that is involved in signaling for its breakdown (degradation) when it is no longer needed.
- As a result of the mutations, the subunit proteins are not degraded, and more ENaC channels remain at the cell surface.
- The increase in channels at the cell surface abnormally increases the reabsorption of sodium (followed by water), which leads to hypertension.
- Reabsorption of sodium into the blood is linked with removal of potassium from the blood, so excess sodium reabsorption leads to hypokalemia.
- TLDR: 當留鈉太多，就要把 K 丟出去