What Is CLN5-Related Neuronal Ceroid Lipofuscinosis?
CLN5-related neuronal ceroid lipofuscinosis (NCL) is an inherited disease that causes degeneration of the brain, leading to a progressive loss of intellectual abilities and motor skills. The condition also causes blindness and seizures and typically leads to an early death. There are several forms of NCL, largely differentiated by the gene responsible and the age at which symptoms begin. Mutations in the CLN5 gene cause a form of NCL that is often referred to as the Finnish variant of late-infantile NCL.
Symptoms of CLN5-related NCL usually begin between the ages of 4 and 7. By the age of 10, children with the condition typically experience loss of vision and develop seizures, intellectual disability, muscle twitching, and an inability to control muscle movements (ataxia). They usually lose the ability to walk independently between 8 and 11 years of age, and will gradually lose their ability to speak and exhibit profound intellectual disability.
How Common Is CLN5-Related Neuronal Ceroid Lipofuscinosis?
NCLs are most common in Scandinavian countries but occur elsewhere as well. The worldwide prevalence of all forms of NCL is estimated to be approximately 1 in 100,000. However, the exact proportion of NCL cases that are caused by mutations in the CLN5 gene is unknown. CLN5-related NCL is known to be most common in Finland.
How Is CLN5-Related Neuronal Ceroid Lipofuscinosis Treated?
There is no treatment for the underlying cause of CLN5-related NCL. Available treatments address the symptoms of the condition as they arise, such as with the use of medications for improving seizures and movement problems.
What Is the Prognosis for an Individual with CLN5-Related Neuronal Ceroid Lipofuscinosis?
The prognosis for an individual with NCL depends on the type of disease he or she has. Those with CLN5-related NCL experience deterioration of motor skills, deterioration of intellectual abilities, and progressive vision loss. Patients will eventually lose the ability to speak and walk independently. The average life expectancy for an individual with CLN5-related NCL typically ranges from 13 to 35 years.