Epidemiology
The only country that Unverricht–Lundborg disease has a reported incidence is in Finland, where it is reported to occur in 4 in 100,000 individuals. However, ULD has only become well defined recently, and it is likely still under diagnosed, so the actual incidence may be different that what is currently known. Other countries with known cases include countries in the Mediterranean region including Italy, France, Tunisia, Algeria, and Morocco, next is Czech Republic  as well as the United States. History
Unverricht–Lundborg disease was first known as one of two different diseases, depending on the location of the individual who had it: Baltic myoclonus or Mediterranean myoclonus. The reason for the different names was partly regional but also because the prognosis of the disease was different for individuals with each due to the way that it was treated in that region. Eventually, both were realized to be the same disease, ULD. Research directions
Many studies have been performed recently to investigate the cause, mechanism, and chemical basis of Unverricht–Lundborg disease. Cystatin B Characteristics
A recent study has attempted to describe the behavior of normal and mutated cystatin B as it is expressed in the body. The results show that cystatin B has a polymeric structure, and that the mutated form of cystatin B, which is present in patients with Unverricht–Lundborg disease, is likely to attract other molecules of cystatin B and form clumps of the molecule. The researchers suggest that this clotting action of the cystatin B molecules may be one of the factors that cause progression of ULD.
Study of Heterozygous Mice
In humans, it is generally known that unless a patient has both recessive CSTB genes (are homozygous recessive), they will not express ULD symptoms. A recent study has attempted to characterize the effects, if any, seen in mice that carry only one recessive CSTB gene (are heterozygous). The researchers analyzed normal and heterozygous mice by having them perform various tasks. The study found that heterozygous mice performed similar to normal mice when the task was started, but as the task continued or became more complex they were more likely to fail. While the results for the heterozygous mice were not remarkably different from the normal mice, they do indicate that carrying just one recessive CSTB gene may have adverse effects, at least in mice. Analysis of EEG as ULD Progresses
Currently, electroencephalography (EEG) is not very effective as a diagnostic tool for Unverricht–Lundborg disease. This study instead looks to characterize the change in EEG of ULD patients as the disease progresses. The researchers studied twenty-five patients with ULD and monitored their EEG over time. The results show that certain brain waves that are present at the beginning of ULD progression and are also present in unaffected individuals, including spontaneous generalized spike or polyspike wave discharges and photoparoxysmal response, tend to decrease after 10 to 15 years. References
External links
Genetics Home References
GeneReviews