What is Degenerin?

Degenerin/Epithelial Sodium Channels (DEG/ENaCs) are a large family of animal-specific non-voltage gated ion channels, with enriched expression in neuronal and epithelial tissues.

What is the ENaC protein?

The epithelial sodium channel (ENaC) is composed of three homologous subunits and allows the flow of Na+ ions across high resistance epithelia, maintaining body salt and water homeostasis.

Is Liddle syndrome pseudohypoaldosteronism?

Liddle’s syndrome, a form of severe hypertension, is caused by gain-of-function mutations and pseudohypoaldosteronism type I, a form of hypovolaemia in infancy, is caused by loss-of-function mutations in ENaC.

Where is ENaC found?

The epithelial sodium channels (ENaC) are located on the apical membrane of epithelial cells in the kidney tubules, lung, respiratory tract, male and female reproductive tracts, sweat and salivary glands, placenta, colon, and some other organs [2,4,6-7,13].

What does the ENaC do?

In the eccrine sweat glands, ENaC is predominantly located in the apical membrane facing the lumen of the sweat ducts. The major function of ENaC in these ducts is the re-uptake of Na⁺ ions that are excreted in sweat.

What is Bartter syndrome?

Bartter syndrome is a general term for a group of rare genetic disorders in which there are specific defects in kidney function. These defects impair the kidney’s ability to reabsorb salt and cause imbalances in various electrolyte and fluid concentrations in the body.

What is Geller syndrome?

Geller syndrome is a rare disease caused by a gain-of-function mutation in the mineralocorticoid receptor resulting from the substitution of leucine for serine at amino acid 810, which is in the hormone-binding domain.

What is Bartter syndrome type 4A?

In Bartter syndrome types 4A and 4B, affected infants cannot hear from birth due to an impaired ability of the auditory nerves to transmit sensory input to the brain (congenital sensorineural deafness).

Which is a disease caused by a mutation in a gene?

Genetic disorders can be caused by the mutation of one or more genes. Cystic fibrosis is one such genetic disorder caused by the mutation in one or more genes. Cancer is another disease caused by the mutation in genes that regulate the cell cycle.

How are dominant mutations related to loss of function?

Dominant mutations, however, may be associated with a loss of function. In some cases, two copies of a gene are required for normal function, so that removing a single copy leads to mutant phenotype. Such genes are referred to as haplo-insufficient.

What causes a change in the DNA sequence?

A mutation is a change in a DNA sequence. Mutations can result from DNA copying mistakes made during cell division, exposure to ionizing radiation, exposure to chemicals called mutagens, or infection by viruses.

What kind of mutations are called dominant negative mutations?

Such genes are referred to as haplo-insufficient. In other cases, mutations in one allelemay lead to a structural change in the protein that interferes with the function of the wild-type protein encoded by the other allele. These are referred to as dominant negative mutations.