How CLN5 Disease Affects the Body

CLN5 disease affects children both cognitively and physically. Symptoms of the disease may include:
Living Batten | CLN5-7 Symptoms Illustration Version 1

Science Behind CLN5 Disease

Living Batten  | CLN5 Inheritance Illustration
The underlying cause of CLN5 disease is found in an individual’s genetic code. In humans, each cell contains 23 pairs of chromosomes for a total of 46: 23 from their mother and 23 from their father. The first 22 pairs of chromosomes are autosomes, and they look the same in both males and females. The 23rd pair are sex chromosomes, which are different between males and females. Females have two copies of the X chromosomes (XX) and males have one X and one Y chromosome (XY). A variant in a gene on one of the first 22 autosomes can lead to an autosomal disease.

Autosomal recessive is one of several ways that a disorder or disease is passed down through families. An autosomal recessive disorder occurs when a child inherits two copies of a mutated gene, one from the mother and one from the father. The biological parents, known as carriers, each carry only one copy of the mutated gene, and usually do not show symptoms of the disease.

CLN5 disease is inherited in an autosomal recessive pattern, meaning both copies of the CLN5 gene variant (one from each parent, or carrier) must be present for the child to be diagnosed with CLN5 disease.

Healthy CLN5 Gene

A healthy CLN5 gene provides the body with instructions for building the CLN5 protein. Although the exact function of the protein is unknown, it is thought to play a role in lysosomal function. In lysosomes, waste is recycled or disposed of properly, resulting in normal cellular function.

Living Batten | CLN5 Healthy Illustration

CLN5 Variant

People with CLN5 disease have a variant on the CLN5 gene, located on chromosome 12. When there is a variant or mutation in the CLN5 gene, the body creates a non-functional CLN5 protein, resulting in lysosomal dysfunction. The lysosome, when unable to function properly, causes a toxic accumulation of material in cells throughout the body.

Living Batten | CLN5 Variant Illustration

Although the CLN5 protein is expressed throughout the body, nerve cells seem to be the most impacted, leading to the central nervous system-related signs and symptoms seen in patients who have CLN5.

 

Sources:

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