Hereditary sensory neuropathy, type II also known as HSN2 is a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 which in humans in encoded by the HSN2. It is a single-exon

Exon

An exon is a nucleic acid sequence that is represented in the mature form of an RNA molecule either after portions of a precursor RNA have been removed by cis-splicing or when two or more precursor RNA molecules have been ligated by trans-splicing. The mature RNA molecule can be a messenger RNA...

 ORF

Open reading frame

In molecular genetics, an open reading frame is a DNA sequence that does not contain a stop codon in a given reading frame.Normally, inserts which interrupt the reading frame of a subsequent region after the start codon cause frameshift mutation of the sequence and dislocate the sequences for stop...

, and a nervous system-specific exon of the WNK1

WNK1

WNK lysine deficient protein kinase 1, also known as WNK1, is an enzyme which in humans is encoded by the WNK1 gene. The human gene is located on short arm of chromosome 12 .WNK1 is also known as Human Accelerated Region 5...

 gene. HSN2 is as an alternatively spliced exon of WNK1 and this selectively occurs in nervous tissues, resulting in WNK1/HSN2 nervous system

Nervous system

The nervous system is an organ system containing a network of specialized cells called neurons that coordinate the actions of an animal and transmit signals between different parts of its body. In most animals the nervous system consists of two parts, central and peripheral. The central nervous...

 isoform

Protein isoform

A protein isoform is any of several different forms of the same protein. Different forms of a protein may be produced from related genes, or may arise from the same gene by alternative splicing. A large number of isoforms are caused by single-nucleotide polymorphisms or SNPs, small genetic...

s.

Function

The WNK1/HSN2 isoforms are expressed in the sensory parts of the peripheral nervous system

Peripheral nervous system

The peripheral nervous system consists of the nerves and ganglia outside of the brain and spinal cord. The main function of the PNS is to connect the central nervous system to the limbs and organs. Unlike the CNS, the PNS is not protected by the bone of spine and skull, or by the blood–brain...

 and central nervous system

Central nervous system

The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...

 which are associated with the transmission of sensory and nociceptive

Nociception

Nociception is defined as "the neural processes of encoding and processing noxious stimuli." It is the afferent activity produced in the peripheral and central nervous system by stimuli that have the potential to damage tissue...

 signals. These parts include satellite cells

Satellite cells

Myosatellite cells or satellite cells are small mononuclear progenitor cells with virtually no cytoplasm found in mature muscle. They are found sandwiched between the basement membrane and sarcolemma of individual muscle fibers, and can be difficult to distinguish from the sub-sarcolemmal nuclei...

, Schwann cell

Schwann cell

Schwann cells or neurolemmocytes are the principal glia of the peripheral nervous system . Glial cells function to support neurons and in the PNS, also include satellite cells, olfactory ensheathing cells, enteric glia and glia that reside at sensory nerve endings, such as the Pacinian corpuscle...

s, and sensory neuron

Sensory neuron

Sensory neurons are typically classified as the neurons responsible for converting external stimuli from the environment into internal stimuli. They are activated by sensory input , and send projections into the central nervous system that convey sensory information to the brain or spinal cord...

s. The novel protein product of the isoform is more plentiful in sensory neurons than motor neuron

Motor neuron

In vertebrates, the term motor neuron classically applies to neurons located in the central nervous system that project their axons outside the CNS and directly or indirectly control muscles...

s. It is proposed that this gene product may play a role in the development and/or maintenance of peripheral sensory neurons or their supporting Schwann cells.

Clinical significance

Mutation

Mutation

In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...

s in the HSN2 gene are associated with congenital sensory neuropathy (HSAN

Hereditary sensory and autonomic neuropathy

Hereditary sensory and autonomic neuropathy or hereditary sensory neuropathy is a condition used to describe any of the types of this disease which inhibit sensation.They are less common than Charcot-Marie-Tooth disease....

Type II), an autosomal recessive disorder characterized by impairment of pain, temperature, and touch sensation owing to reduction or absence of peripheral sensory neurons.