SNP Shot: Genomic Insights

CLN6 disease is a genetic condition that mainly impacts the nervous system. While symptoms usually emerge in childhood (ranging from early to late childhood), some individuals may not experience them until adulthood.

The majority of children affected by CLN6 disease initially experience a decline in skills they previously mastered (developmental regression). Other common features include recurring seizures (epilepsy), coordination difficulties (ataxia), involuntary muscle jerks (myoclonus), slurred speech (dysarthria), and vision impairment. These movement problems worsen progressively, eventually leading to a loss of the ability to walk, stand, or sit independently. Cognitive decline also occurs over time, and most children with CLN6 disease do not live to adulthood.

A smaller number of individuals with CLN6 disease remain symptom-free until adulthood, typically after age 30. These adults may develop epilepsy, ataxia, dysarthria, and a gradual decline in intellectual abilities. Unlike the childhood form, vision loss is generally not a feature of CLN6 disease in adults. The life expectancy for adults with CLN6 disease is often limited to about 10 years following diagnosis.

CLN6 disease belongs to a group of neurodegenerative disorders known as neuronal ceroid lipofuscinoses (NCLs), also known as Batten disease. These disorders all affect the nervous system, leading to progressive problems with vision, movement, and cognitive function. The different NCL types are distinguished by their specific genetic cause, and are categorized using the "CLN" designation (ceroid lipofuscinosis, neuronal) followed by a number indicating the subtype.

Inheritance:

CLN6 disease follows an autosomal recessive inheritance pattern. This means that an individual must inherit two copies of the mutated gene (one from each parent) to develop the condition. The parents, who each carry a single copy of the mutated gene, are typically unaffected carriers and do not display signs or symptoms of the disease themselves.