Frequently Asked Questions about Batten Disease

 

What is Batten disease?

• Batten disease is a rare genetically inherited disorder which belongs to a group of progressive degenerative neurometabolic disorders, known as the neuronal ceroid lipofuscinoses (NCLs).[1] 
• NCLs are characterized by genetic mutations which disrupt cells' ability to dispose of wastes, resulting in the abnormal accumulation of certain proteins and lipids (fats) within the nerve cells of the brain and other tissues of the body, resulting in progressive neurological impairment including developmental regression, seizures, blindness, behavior changes and dementia.
• There are many forms of NCL. Mutations in at least eight different genes are known to cause Batten disease.[2] 
• Charlotte and Gwenyth have been diagnosed with Late Infantile Batten disease, caused by mutation(s) in the CLN6 gene. This particular variant is extremely rare and the disease course can differ significantly among cases, making it difficult to predict.

What are the symptoms and when do they become apparent?

• Early symptoms of Batten disease include progressive vision loss, seizures, behavioral changes, and loss of motor skills in previously healthy children. Symptoms get progressively worse, resulting in blindness, Parkinson-like symptoms and dementia.
• The different variants of the disease are distinguishable from one another in part by the age at which symptoms appear. Symptoms can appear as early as 6 months and as late as 43 years old. Children affected by Late Infantile Batten disease, including Charlotte and Gwenyth, typically begin to show symptoms between ages 2 to 4.[3] 

How is it inherited and how is it diagnosed?

• Batten disease is inherited as an autosomal recessive trait, meaning the same abnormal gene for the same trait is inherited from each parent. Both parents must be carriers and pass on the defective gene. The risk for two carrier parents to both pass the defective gene is 25% with each pregnancy. 1
• Typically, diagnosing Batten disease requires a combination of testing including blood or urine tests, skin or tissue sampling, EEG, electrical study of the eyes, brain scan using CT or MRI, and enzyme activity measurement. The only definitive diagnosis for Batten disease is through DNA analysis.[4] 
• Due to its rarity, diagnosing Batten disease is typically a long, painful journey for families who receive many false diagnoses before the final Batten determination.

How rare is Batten disease?

• Batten disease and other forms of NCL are rare – occurring in an estimated 2 to 4 of every 100,000 live births in the United States.2
• Late Infantile Batten disease, particularly CLN6 which Charlotte and Gwenyth have, is especially rare. It is estimated that less than 10 children are currently living with this variant of the disease, though exact numbers are difficult to pinpoint.

What is the prognosis?

• As Batten disease is currently untreatable, those affected will eventually become bedridden, fully dependent on their families or caretaker, and face premature death. Depending on the variant, Batten patients' life expectancies can range from as young as 6 to adulthood (in the case of adult onset Batten disease).
• Those impacted with Late Infantile Batten disease are expected to live incredibly short lives – with life expectancies between the ages of 6 to 12 years old.

 [1] "Batten Disease." NORD (National Organization for Rare Disorders). http://rarediseases.org/rare-diseases/batten-disea... 

 [2] "Batten Disease Fact Sheet." National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/batten/detail_b... 

 [3] "Understanding Batten – Prognosis." Beyond Batten Disease Foundation. http://beyondbatten.org/understanding-batten/progn... 

 [4] "Understanding Batten – Diagnosis/Symptoms." Beyond Batten Disease Foundation. http://beyondbatten.org/understanding-batten/diagn...