Neuronal Ceroid Lipofuscinosis Type II (Batten Disease)
What is neuronal ceroid lipofuscinosis type II?
Neuronal ceroid lipofuscinosis type II (CLN2), also called Batten disease, is caused by the body not having enough of a specific enzyme called tripeptidyl peptidase 1. Without normal levels of this enzyme in the body, certain proteins build up and cause damage to nerve cells. The early signs of CLN2 may include seizures, difficulty with walking, and vision loss. These symptoms can appear between the ages of 2 and 4 years. Intellectual development also slows as the condition progresses.
How common is CLN2?
About 1 in 500,000 babies are born with CLN2 each year in the United States.
What can be done for CLN2?
Identifying this condition early (soon after birth) may lead to reduced symptoms and an improved quality of life. Certain symptoms of this condition can be treated with physical and occupational therapies. There is also a form of treatment that replaces the missing tripeptidyl peptidase 1 enzyme - this is called enzyme replacement therapy (ERT). While ERT isn’t a complete cure for CLN2, it can make many of the symptoms less severe, helping people with CLN2 live longer, fuller lives.
How is CLN2 inherited?
CLN2 is caused by changes in the TPP1 gene. It is a recessive inherited condition, which means that a person must inherit two altered copies of the TPP1 gene, one from each parent, in order to have the disease. People who have only one copy of the altered TPP1 gene are called carriers, and are not expected to have symptoms of the condition. If a baby is identified as a carrier for CLN2 through Eli screening, genetic counseling and additional testing in the parents is recommended.