Juvenile Batten disease

Juvenile Batten disease is an inherited disorder that primarily affects the nervous system. Beginning in childhood, affected individuals develop progressive vision loss, seizures, and intellectual decline.

Vision loss is often the first noticeable sign of juvenile Batten disease, beginning between the ages of 4 and 8 years. Vision loss tends to worsen rapidly, leading to blindness. Recurrent seizures begin between the ages of 5 and 18 years.

Children with juvenile Batten disease experience a decline in thinking ability (cognition) that worsens with time. They often have behavioral problems, difficulty sleeping, speech abnormalities, and problems with attention that appear in mid- to late childhood. Affected children also develop movement abnormalities similar to those associated with Parkinson disease. These include rigidity or stiffness, slow or diminished movements (hypokinesia), and stooped posture. Affected children may stumble and shuffle their feet when they walk.

As the condition progresses, affected people lose the ability to walk and perform other activities of daily living. They ultimately require comprehensive care. Most people with juvenile Batten disease live into their teens or twenties, although some affected individuals have lived into their thirties.

Juvenile Batten disease is one of a group of disorders known as neuronal ceroid lipofuscinoses (NCLs). These disorders all affect the nervous system and cause progressive problems with vision, movement, and cognition. Some people refer to the entire group of NCLs as Batten disease, while others limit that designation to the juvenile form of the disorder.

Juvenile Batten disease is the most common type of NCL, affecting 2 to 4 per 100,000 newborns in the United States. This condition has been reported worldwide.

Juvenile Batten disease results from mutations in the CLN3 gene. This gene provides instructions for making a protein whose function is unknown. However, it appears to play a critical role in the survival of nerve cells (neurons) in the brain.

It is unclear how mutations in the CLN3 gene lead to the characteristic features of juvenile Batten disease. These mutations somehow disrupt the function of cellular structures called lysosomes. Lysosomes are compartments in the cell that normally break down toxic substances and recycle different types of molecules. In people with juvenile Batten disease, a fatty substance called a lipopigment builds up abnormally within lysosomes. The buildup of this substance is thought to damage neurons and may ultimately cause these cells to die. Over time, the progressive death of neurons in the brain leads to vision loss, seizures, and cognitive decline in affected individuals.

Although lipopigment also accumulates within other types of cells, the signs and symptoms of juvenile Batten disease primarily affect the brain. Studies suggest that neurons may be particularly vulnerable to damage caused by the buildup of lipopigment in lysosomes.

Read more about the CLN3 gene.

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.