|http://ghr.nlm.nih.gov/ A service of the U.S. National Library of Medicine®|
The official name of this gene is “chloride channel, voltage-sensitive Ka.”
CLCNKA is the gene's official symbol. The CLCNKA gene is also known by other names, listed below.
The CLCNKA gene belongs to the CLC family of genes, which provide instructions for making chloride channels. These channels, which transport negatively charged chlorine atoms (chloride ions), play a key role in a cell's ability to generate and transmit electrical signals. Some CLC channels regulate the flow of chloride ions across cell membranes, while others transport chloride ions within cells.
The CLCNKA gene provides instructions for making a chloride channel called ClC-Ka. These channels are found predominantly in the kidneys. ClC-Ka is one of several proteins that work together to regulate the movement of ions into and out of kidney cells. The transport of chloride ions by ClC-Ka channels is part of the mechanism by which the kidneys reabsorb salt (sodium chloride or NaCl) from the urine back into the bloodstream. The retention of salt affects the body's fluid levels and helps maintain blood pressure.
ClC-Ka channels are also located in the inner ear, where they play a role in normal hearing.
Several people with Bartter syndrome have had mutations in both the CLCNKA gene and a closely related gene called CLCNKB. The CLCNKB gene provides instructions for making a very similar chloride channel, ClC-Kb, that is also found in the kidneys and inner ear. A combination of CLCNKA and CLCNKB gene mutations causes a life-threatening form of the disorder called Bartter syndrome type IV. This condition is also known as antenatal Bartter syndrome with sensorineural deafness because affected individuals have hearing loss caused by abnormalities in the inner ear.
Mutations in the CLCNKA and CLCNKB genes prevent the ClC-Ka and ClC-Kb channels from transporting chloride ions in the kidneys. As a result, the kidneys cannot reabsorb salt normally and excess salt is lost through the urine (salt wasting). The abnormal salt loss disrupts the normal balance of ions in the body. This imbalance underlies many of the major features of Bartter syndrome, including a failure to grow and gain weight at the expected rate (failure to thrive), dehydration, constipation, and increased urine production (polyuria). A loss of ClC-Ka and ClC-Kb function in the inner ear is responsible for the hearing loss characteristic of Bartter syndrome type IV.
Studies suggest that several normal variants (polymorphisms) in the CLCNKA gene may be associated with salt-sensitive hypertension, a form of high blood pressure related to increased levels of salt in the blood. However, this association between CLCNKA polymorphisms and hypertension has not been confirmed. Changes in the CLCNKA gene may affect blood pressure by altering the kidneys' ability to reabsorb salt into the bloodstream.
Cytogenetic Location: 1p36
Molecular Location on chromosome 1: base pairs 16,348,485 to 16,360,544
The CLCNKA gene is located on the short (p) arm of chromosome 1 at position 36.
More precisely, the CLCNKA gene is located from base pair 16,348,485 to base pair 16,360,544 on chromosome 1.
See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.
You and your healthcare professional may find the following resources about CLCNKA helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.
cell ; channel ; chloride ; chloride channels ; constipation ; dehydration ; failure to thrive ; gene ; hypertension ; ions ; kb ; kidney ; NaCl ; polyuria ; protein ; sensorineural ; sodium ; sodium chloride ; syndrome ; voltage ; wasting
You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.