Batten Disease | Overview
What is Batten disease?
Batten disease is a very rare genetic disorder that affects the brain and nervous system. Symptoms sometimes begin in infancy and sometimes later in childhood, after apparently normal early development. Occasionally it may start in adulthood. In individuals suffering from Batten disease, nervous system function steadily declines, causing a wide variety of neurologic problems, including loss of vision and seizures.
The life expectancy of a child born with Batten disease can vary, depending on the form of the disease and the age of onset. Some children die in early childhood, while others may be able to live into their teens or twenties.
Worldwide, roughly 14,000 children are known to have Batten disease. In the U.S., it affects an estimated 2 to 4 out of every 100,000 children. There is currently no cure.
What causes Batten disease?
Batten disease is actually a family of related disorders also known as neuronal ceroid lipofuscinoses. It can be caused by genetic mutations in any of more than a dozen known genes, collectively referred to as CLN genes (CLN1, CLN2, etc). Because the disease is recessive, children must have two copies of a CLN mutation — one from each parent — to be affected. Siblings of affected children have a one in four chance of also developing the disease, and a 50 percent chance of being a carrier.
How CLN mutations lead to Batten disease isn’t fully known, but they are thought to interfere, in different ways, with cells’ ability to break down and recycle their waste products. This function is performed by lysosomes, which act as the cell’s “trash cans,” and Batten disease is therefore classified as a lysosomal storage disorder. The cells try to compensate by making more lysosomes, which get larger and larger and eventually release their contents into the cell. The cells eventually get overwhelmed and die. Cells in the nervous system seem to be especially vulnerable.
What are the symptoms of Batten disease?
Most forms of Batten disease cause vision loss, seizures, delayed developmental milestones, behavioral and learning problems, and loss of language and motor skills. Some children with infantile Batten disease also develop microcephaly.
Vision loss is often the first symptom and can rapidly progress. Parents also often notice clumsiness and stumbling in older children due to a loss of motor coordination. Eventually, children with Batten disease become blind, unable to walk, talk, or swallow, and confined to a wheelchair or bed.
How we care for Batten disease
Because Batten disease has many genetic causes, we recommend testing through Clinical Genetics, within the Division of Genetics and Genomics, to identify the specific subtype and the underlying mutation. This will help us predict what future course the disease might take, and may be helpful in choosing treatments.
Our Lysosomal Storage Disease Program within Genetics and Genomics offers coordinated, patient-centered care and access to top specialists in Neurology, Ophthalmology, Physiotherapy, and others as needed. Our team in the Department of Neurology can evaluate children with Batten disease over time and may recommend treatments such as antiseizure drugs and other medications to improve quality of life.
Batten Disease | Diagnosis and Treatment
How is Batten disease diagnosed?
Batten disease is most definitively diagnosed by genetic testing, often as part of a panel of genetic tests used in children with epilepsy or unexplained seizures. Eye exams, blood or urine tests and skin sampling can often identify changes that signal Batten disease, which can then be confirmed with genetic testing. Brain magnetic resonance imaging (MRI) scans and electroencephalograms (EEGs) are often abnormal in children with Batten disease, but are not definitive enough to be used for diagnosis.
What are the treatment options for Batten disease?
Unfortunately, there is currently no treatment that can reverse Batten disease. However, an enzyme replacement therapy recently became available for children with CLN2 mutations that appears to slow disease progression. Gene therapy is also being investigated, with the goal of replacing the mutated genes that cause Batten disease with healthy, functioning copies. Other drug and enzyme therapies are also in early stages of investigation.
In the meantime, some existing treatments can help control the symptoms of Batten disease and improve children’s quality of life — such as antiseizure drugs, treatments for spasticity, medications for anxiety and other behavioral symptoms, and physical and occupational therapy. These treatments cannot cure Batten disease but can help children retain their abilities for as long as possible.
Researchers at Boston Children’s Hospital are hopeful that some forms of Batten disease could be treated with oligonucleotide drugs, synthetic pieces of genetic code that can be customized to home in to a specific part of a child’s DNA and fix or ameliorate the effects of their mutation.