Biology of CLN5, a Subtype of Batten Disease
How CLN5 Disease Affects the Body
CLN5 disease affects children both cognitively and physically. Symptoms of the disease may include:
Science Behind CLN5 Disease
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 Inheritance characteristic where a gene is located on a numbered, non-sex chromosome. These are found on one of the 22 pairs of (44 total) autosomal chromosomes in a human body where DNA is stored. This is one of several ways that a trait, disorder, or disease can be passed down through families. These chromosomes are not the sex (X or Y) chromosomes. 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.
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.
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.
- CLN5 gene. (2019, December 10) Retrieved December 17, 2019, from link.
- CEROID LIPOFUSCINOSIS, NEURONAL, 5; CLN5. (2016, March 15). Retrieved June 20, 2019, from link.
- CLN5 disease. (n.d.). Retrieved June 19, 2019, from link.
- CLN5 disease. (2019, June 11). Retrieved June 19, 2019, from link.
- CLN5 gene. (2016, November). Retrieved June 20, 2019, from link.
- Neuronal ceroid lipofuscinosis 5. (n.d.). Retrieved June 20, 2019, from link.