Genetic basis of Parkinson's disease and related disorders (original) (raw)

Additional non-motor features like postural abnormalities, dysautonomia, dystonic cramps, anxiety, depression or dementia are characteristic. Most of these symptoms tend to get worse over time. The term parkinsonism refers to a syndrome including a combination of all these clinical features as well as many other diseases which most likely result from loss or dysfunction 1.2. EPIDEMIOLOGY Data on the prevalence and incidence of PD are of interest for several reasons. Epidemiological studies can provide insights into suspected risk factors, protective factors and primary causes of the disease;, these data can also provide critical information to inform public health planning. This latter point has become of special interest in the last years, as longevity of the population increases and the incidence of PD rises with age. Since PD was first described, a number of epidemiological studies have been performed. However, since these studies were methodologically limited, being mostly small casecontrol or register-based studies, it was not until the end of the twentieth century that large studies reached a stage with sufficient number of PD patients to examine incidence and potential risk factors. A limitation of this work is that a reliable and easily applicable Rijk, Launer et al., 2000). De Lau and colleagues reviewed age-specific prevalence rates obtained from studies across different populations (figure 1). This review clearly shows that PD is an age-related disease, being rare before 50 in all reviewed populations (De Lau and Breteler, 2006). As the elderly population increases in size, the prevalence of PD increases as well, making prevalence studies difficult to perform. From an etiological point of view, PD may result from different environmental exposition and genetic background that are both due to intercultural differences. Some studies have