SCNN1B

SCNN1B is a gene that encodes the beta subunit of the epithelial sodium channel (ENaC). ENaC is a part of the aldosterone-sensitive sodium reabsorption pathway in the kidney, lung, and sweat glands. Mutations in this gene have been associated with a variety of conditions, including Liddle syndrome, pseudohypoaldosteronism type 1 (PHA1), and cystic fibrosis.

Function

The SCNN1B gene is responsible for the production of the beta subunit of the epithelial sodium channel (ENaC). This channel is found in the plasma membrane of many epithelial cells, where it allows for the passage of sodium ions into the cell. The activity of ENaC is regulated by the hormone aldosterone, which is produced by the adrenal gland in response to low blood volume or low sodium concentration.

Clinical significance

Mutations in the SCNN1B gene can lead to a variety of conditions. For example, Liddle syndrome is a rare genetic disorder characterized by early-onset hypertension, low levels of aldosterone, and suppressed plasma renin activity. This condition is caused by gain-of-function mutations in the SCNN1B gene that result in increased activity of ENaC.

Pseudohypoaldosteronism type 1 (PHA1) is another condition associated with mutations in the SCNN1B gene. PHA1 is characterized by salt wasting, hyperkalemia, and metabolic acidosis. This condition is caused by loss-of-function mutations in the SCNN1B gene that result in decreased activity of ENaC.

In addition, mutations in the SCNN1B gene have been associated with cystic fibrosis, a condition characterized by the buildup of thick, sticky mucus that can damage many of the body's organs.

See also

• Epithelial sodium channel
• Liddle syndrome
• Pseudohypoaldosteronism
• Cystic fibrosis