SNP Shot: Genomic Insights

CLN2 disease is a genetic condition that mainly impacts the nervous system. Symptoms usually appear between the ages of 2 and 4, often starting with repeated seizures (epilepsy) and problems with balance and coordination (ataxia). Children affected by CLN2 disease may also experience involuntary muscle jerks (myoclonus) and vision impairment. The disease impairs motor skills like sitting, walking, and speaking. Furthermore, it leads to a decline in previously learned abilities (developmental regression), increasing intellectual disability, and behavioral issues. Many affected individuals require wheelchair assistance by late childhood and usually don't live beyond their teenage years.

In some cases, CLN2 disease symptoms emerge later in childhood, generally after the age of 4. While these individuals typically experience milder symptoms compared to those diagnosed earlier, they often have more significant ataxia. Their lifespan is reduced, but they tend to live into adulthood.

CLN2 disease belongs to a group of conditions called neuronal ceroid lipofuscinoses (NCLs), also known as Batten disease. These disorders affect the nervous system, typically causing progressive issues with vision, movement, and cognitive function. The different NCLs are classified based on their underlying genetic cause, and each type is labeled "CLN" (ceroid lipofuscinosis, neuronal) followed by a number indicating the specific subtype.

Inheritance:

CLN2 disease follows an autosomal recessive inheritance pattern. This means that an individual must inherit two mutated copies of the responsible gene, one from each parent, to develop the condition. The parents, who each carry only one copy of the mutated gene, usually do not exhibit any signs or symptoms of the disease.