Biomarkers in rare diseases

Nowadays 7,000 rare diseases (RDs) have been identified with a prevalence less than 5/10,000. Despite of the enormous effort the European Union (EU) has already invested in this field, still 4,000 RDs remain orphan of genetic diagnosis and causative gene identification. The genetic definition of RDs represents a prerequisite for being diagnosed, for having a robust prevention, for entering in a specific standard of care, and ultimately, for being included in clinical trials, often via personalized medicine. It is well established that biomarkers can offer a way to speed up research by understanding the pathophysiological mechanisms of diseases. In particular, biomarkers will offer an invaluable tool for monitoring disease progression, prognosis and response to drug treatment.

In this review, we summarize the different types of biomarkers and their importance as well as their translational applications in RDs. We have reviewed the current knowledge on biomarkers state-of-the-art via literature data, specific websites and EU sources regarding past, pending and current projects.

Here we provide a comprehensive scenario of biomarkers research, its applications in clinical practice, with special emphasis on translational research applicable to diagnostic and clinical trials. The experience of the EU project BIO-NMD is also mentioned.

Biomarkers represent key features in both diagnostics and research on rare diseases and will encounter wide exploitation in translational and personalized medicine.