Scientists from Walter and Eliza Hall Institute and University of Melbourne have used new technologies to identify the gene responsible for Kufs, a rare but fatal hereditary brain disorder. According to the scientists, the discovery will make it possible to diagnose the disease through a blood test rather than a brain biopsy.
Dr Melanie Bahlo, Katherine Smith and Catherine Bromhead from Walter and Eliza Hall Institute’s Bioinformatics division, in collaboration with neurologist and epilepsy specialist Dr Sam Berkovic and Dr Todor Arsov from University of Melbourne, have found that mutations in the CLN6 gene on chromosome 15 are the cause of inherited recessive Kufs type A disease.
Kufs disease is a rare but fatal, hereditary neurodegenerative disease usually identified in early adulthood. Brain symptoms result from a build up of fat in brain cells that is toxic to the cells, causing symptoms including epilepsy, dementia, impaired motor function and intellectual deterioration. It affects approximately 1 in 1,000,000 people.
According to Dr Sam Berkovic, head of Epilepsy Research Centre at University of Melbourne and the Comprehensive Epilepsy Programme at Austin Health, identification of the CLN6 gene will enable more efficient and much less invasive techniques for earlier diagnosis of Kufs disease.
“Currently, the only way that we can reliably diagnose this disease is to do an invasive and dangerous brain biopsy, or at autopsy,” says Dr Sam Berkovic. “The discovery of the gene at the root of Kufs type A disease will enable us to use a rapid and simple blood test to genetically test for the disease. It will also give us the ability to screen for the disease in people in at-risk families, and make it possible for genetic counselling, which we already know to be very important for patients.”
Dr Melanie Bahlo and Katherine Smith’s innovative work used data generated from a person’s DNA, called SNP genotyping. When combined with sophisticated mathematical and statistical analysis, the information helped them identify the region in the human genome likely to contain the DNA error that causes Kufs disease, which led to discovery of the gene mutations.
“The genetic cause of Kufs disease has remained a mystery for over 25 years, because the rarity of the condition meant that our patient groups were so small we couldn’t reliably pinpoint any particular genetic mutations that caused their disease,” says Dr Melanie Bahlo.
“In this study, we used an innovative suite of highly specialised techniques and statistical algorithms that compensated for the small sample size and allowed us to look at the entire genetic code of people with Kufs disease to find which region of the DNA had the mutation which caused disease. Discovering the CLN6 gene as the cause of Kufs disease is a great outcome for us and for the people who are affected by this awful disease,” adds Dr Melanie Bahlo.
According to Dr Sam Berkovic, the best possible outcome from the study will be the development of a treatment for Kufs disease, which is currently untreatable and invariably fatal. “The general aim and hope of this work is always to be able to use the discovery to translate to a treatment, but this is still some time away,” he says.
According to Dr Melanie Bahlo, the innovative study used to find the gene responsible for Kufs disease could hold the key for finding the genetic cause of a number of other hereditary diseases including other epilepsy-related diseases, deafness and some familial cancers.
“These new techniques for using statistical data and mathematical algorithms to track down the genetic basis of disease are really at the forefront of medical research today,” says Dr Melanie Bahlo. “Finding the genes responsible for certain diseases will help us in our quest to generate new diagnostic tools as well as provide the basis for fundamental biology that leads to development of new drugs and therapies to treat disease.”