adoption of diagnostic testing in clinical practice. Moreover, the natural history of these disorders is not well described and it is not known what determines differences in outcomes. New therapies are needed. For existing therapies, high-quality evidence
on short- and long-term efficacy and safety is generally lacking. Therefore, the purpose of this study is to provide a better understanding of the natural history of these disorders, as affected by available therapies, and to aid in developing new forms of treatment.
