Batten disease is a rare heritable disease that affects around 1 in 100,000 births worldwide. Also called neuronal ceroid lipofuscinosis (NCL), the disease is caused by mutations in genes that encode for proteins responsible for handling cellular wastes.
The mutations cause proteins to be made incorrectly (or not at all), so cellular wastes called lipofuscins build up inside cells. These cellular wastes cause neurodegeneration (death of nerve cells) and lead to many of the symptoms of Batten disease.
Genetics of Batten disease
Batten disease is an autosomal recessive disorder, meaning that in order to develop the disease, patients have to have two copies of a disease-causing gene, one copy inherited from each parent.
People who have only one copy of a disease-causing gene do not develop the disease but can pass it onto their children. If both parents have one copy each of the disease-causing gene, their children have a 1-in-4 chance of developing Batten, a 1-in-2 chance of being a carrier (like their parents), and a 1-in-4 chance of neither being a carrier nor developing the disease.
Genetic testing
Batten disease is often misdiagnosed, especially in the early stages. Many of the early symptoms can be subtle, such as clumsiness or personality changes. The only sure way to diagnose Batten disease is through genetic testing.
To perform a genetic test for Batten disease (or other genetic condition), the patient’s DNA is purified from a blood sample. The DNA is then sequenced – where the exact DNA sequence of the gene is determined. Until recently, genetic screens were performed for one gene at a time, and each screen could cost between $200 and $1,200 for each gene that was tested. Currently, there are 14 genes known to cause Batten disease, but to test for every gene, one by one, would be prohibitively expensive for most people.
Genetic screens are now getting faster, more accurate, and less expensive. A new screen called “TaGSCAN” (targeted gene sequencing and custom analysis) has been clinically validated to identify 750 rare diseases, including the different types of Batten disease. The test costs about the same as sequencing a single gene, because it sequences many genes in parallel.
TaGSCAN is now available and can be ordered by any qualified physician who suspects his or her patient has a genetic illness. Patients have a small amount of blood (5 mL) drawn at the doctor’s office or clinic. The sample is then sent for testing. DNA is isolated from the sample, and a machine tests the DNA for the presence of disease-causing mutations.
A positive test for any of the disease-causing genes may then be confirmed by traditional sequencing methods. This additional test usually does not add to the cost of the procedure, and no additional patient samples are likely to be required.
Results usually become available within six to eight weeks from the time the sample is submitted. The patient’s physician or genetic counselor can then discuss the interpretation of the results of the screen, and advise patients and their families on treatment plans if necessary.
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Batten Disease News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.