CLN6-related neuronal ceroid lipofuscinosis (NCL6) is an inherited disorder known for its brain degeneration, leading to a gradual deterioration of both mental faculties and motor skills.
Within the realm of NCL, there exist various forms, primarily distinguished by the specific gene responsible and the age when symptoms manifest. Mutations in the CLN6 gene typically give rise to variant late-infantile neuronal ceroid-lipofuscinosis (vLINCL) or, on rare occasions, adult-onset NCL (Kufs disease type A).
In vLINCL, symptoms typically initiate between the ages of 3 and 8. Early indications often encompass seizures, vision impairment, and difficulties in motor coordination. Additional symptoms include involuntary movements, cognitive decline, and speech impairments. Generally, most children with vLINCL will lose both motor skills and vision by the age of 4 to 10, with a life expectancy of around 20 years.
Conversely, adult-onset NCL tends to manifest around the age of 30, although it can occur anywhere from 16 to 51 years. Affected individuals face challenges in controlling seizures, experience dementia, and encounter difficulties in maintaining balance and coordinating movements. Unlike vLINCL, vision remains unaffected in adult-onset NCL, with death typically occurring approximately a decade after the onset of symptoms.
NCL6 is caused by pathogenic (disease-causing) variants in the CLN6 gene and exhibits autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background.
Other names for this condition are ceroid lipofuscinosis neuronal 6 and neuronal ceroid lipofuscinosis 6.