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CLN8

CLN8

Reviewed September 2013

What is the official name of the CLN8 gene?

The official name of this gene is “ceroid-lipofuscinosis, neuronal 8 (epilepsy, progressive with mental retardation).”

CLN8 is the gene's official symbol. The CLN8 gene is also known by other names, listed below.

Read more about gene names and symbols on the About page.

What is the normal function of the CLN8 gene?

The CLN8 gene provides instructions for making a protein whose precise function is not known but is thought to play a transport role within cells. Specifically, the CLN8 protein likely helps to transport materials in and out of a cell structure called the endoplasmic reticulum, which is involved in protein production, processing, and transport. Based on the structure of the CLN8 protein, it may also be involved in regulating the levels of fats (lipids) in cells.

How are changes in the CLN8 gene related to health conditions?

late-infantile neuronal ceroid lipofuscinosis - caused by mutations in the CLN8 gene

At least 20 mutations in the CLN8 gene have been found to cause late-infantile neuronal ceroid lipofuscinosis (NCL). This condition impairs motor and mental development beginning in early childhood, causing movement disorders and a decline in intellectual function. In addition, affected children often develop recurrent seizures (epilepsy) and vision impairment. Most of the CLN8 gene mutations that cause late-infantile NCL change single protein building blocks (amino acids) in the CLN8 protein, likely decreasing protein activity.

Fatty substances called lipopigments accumulate in cell structures called lysosomes of people with late-infantile NCL. Lysosomes digest and recycle different types of molecules. These accumulations can result in cell dysfunction and eventually cause cell death, especially in brain cells, which are particularly vulnerable to damage caused by lipopigments. However, it is unclear how mutations in the CLN8 gene are involved in the buildup of lipopigments and the signs and symptoms of late-infantile NCL.

Late-infantile NCL caused by CLN8 gene mutations was once thought to be specific to people of Turkish descent. While CLN8 gene mutations are a frequent cause of the disorder in this population, mutations in this gene have since been found in populations worldwide.

Northern epilepsy - caused by mutations in the CLN8 gene

Nearly all individuals with Northern epilepsy have the same mutation in both copies of the CLN8 gene in each cell. Northern epilepsy is a type of NCL characterized by recurrent seizures beginning in childhood followed by intellectual decline and movement problems. The mutation that causes this condition replaces the amino acid arginine with the amino acid glycine at position 26 in the CLN8 protein (written as Arg26Gly or R26G). The effects of this mutation on protein function are unclear.

Unlike other forms of NCL that result in the accumulation of large amounts of lipopigments in cells, Northern epilepsy is associated with very little lipopigment buildup. People with Northern epilepsy do develop mild brain abnormalities resulting from cell death, but the cause of this brain cell death is unknown. It is also unclear how changes in the CLN8 protein and a loss of brain cells cause the neurological problems associated with Northern epilepsy.

Where is the CLN8 gene located?

Cytogenetic Location: 8p23

Molecular Location on chromosome 8: base pairs 1,755,777 to 1,786,569

The CLN8 gene is located on the short (p) arm of chromosome 8 at position 23.

The CLN8 gene is located on the short (p) arm of chromosome 8 at position 23.

More precisely, the CLN8 gene is located from base pair 1,755,777 to base pair 1,786,569 on chromosome 8.

See How do geneticists indicate the location of a gene? in the Handbook.

Where can I find additional information about CLN8?

You and your healthcare professional may find the following resources about CLN8 helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the CLN8 gene or gene products?

  • C8orf61
  • CLN8_HUMAN
  • EPMR
  • FLJ39417

Where can I find general information about genes?

The Handbook provides basic information about genetics in clear language.

These links provide additional genetics resources that may be useful.

What glossary definitions help with understanding CLN8?

acids ; amino acid ; arginine ; cell ; ceroid ; endoplasmic reticulum ; epilepsy ; gene ; glycine ; mental retardation ; motor ; mutation ; neurological ; population ; protein

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.

See also Understanding Medical Terminology.

References (8 links)

 

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? in the Handbook.

 
Reviewed: September 2013
Published: January 27, 2015