Rare diseases and omics-driven personalized medicine

By definition, a rare disease affects fewer than one indi-vidual in 2000 people in the general population. However, as there are nearly 8000 rare diseases (some even without a name), it turns out that these “rare” diseases affect more than 300 million people worldwide (about 6% of the world’s population). Rare diseases, however, take a disproportionately high share of the health budget, estimated at about 20%. Some of them affect only a few individuals, while others affect hundreds of thousands. Regardless of whether a single rare disease affects millions or just one person, it has enormous medical and social implications, and its impact on the affected individuals and their families is generally devastating. This is especially the case because over 50% of rare diseases affect children, almost half of whom die before the age of 10. Historically, rare diseases have become also known as orphan diseases because pharmaceutical companies were not interested in developing treatments for them. However, after much struggle by parents’ non-profit organizations (eg, Families of SMA, Cure SMA, among others), and through the SMA Treatment Acceleration Act, in 2009 SMA entered the list of top 50 medical priorities in the USA. After a series of clinical trials, on December 23, 2016 these joint efforts finally resulted in the approval by the Food and Drug Administration of nusinersen (Spinraza), a medication for all types of SMA. This example shows how a deeper understanding of the genome and disease pathogenesis, combined with energetic involvement of families, may change clinical research and drug development. These efforts could also pave the way for the replacement of larger classifications of common disorders with more precisely defined individual diseases based on genetic markers.