For a neurodegenerative disease that strikes later in life with neuronal dysfunction and subsequent cell death by showing a mind-boggling heterogeneity of subtypes, spinocerebellar ataxia had not been adequately tackled for a long time. That is, until the EUROSCA project came along with its rationale of “combining for the first time different group of SCAs and putting together the patients across Europe”, as the coordinator, Prof. Olaf Riess from Tuebingen University in Germany says.
SCAs are progressive movement disorders, involving loss of balance and motor coordination of the arms and legs. The problem is that, although the disease is inherited, it is often not detected until later in life, which means that by the time it develops, patients may already be 20 or 30, or perhaps even 40, and with children of their own. The fact is, 50% of the offspring gets the disease. All in all, the incidence in the population is approximately 1 in 10,000 and there is no cure.
Which explains the reason why a European SCA Registry (EUROSCA-R), which is now the largest and best characterized in the world with over 3,300 patients and setting the clinical standards for years to come, was the best way to develop linkage analysis that has led scientists to identify new SCA loci and to the cloning of new ataxia genes.
The project’s other achievements, funded with 9,45 million euros by the European Commission and involving 22 European teams from 9 countries, include a new clinical rating scale, structural imaging and electrophysiology. The aim is to decipher the pathogenesis of SCA subtypes and develop a treatment.
“We have rated the patients according to the disease phenotype”, Prof. Riess explains, “to establish the progression of the disease and the sub-forms correctly , so that a treatment can be efficient. Our consortium has produced this rating scale. The disease is fatal and we have a big responsibility towards these patients, who really suffer”.
This concerted European action also offers a new systematic large-scale search for genetic modifier factors in SCAs. “We have also been very successful with drosophila (fruit flies, Ed.), in which we produced a phenotype whereby we can see if there is a neural degeneration of the eye that is due to SCA”, Professor Riess adds. “We are trying to develop a drug that might be able to get over the blood-brain barrier and we are investigating the genetic causes of the disease. We also identified some new ataxia genes. It is usually very difficult for a neurologist to identify the type of SCA, since most symptoms are similar: spasticity, stiffness, tremor, uncontrolled eye movements”.