A disease is classified as rare if it affects less than six patients per 10,000 people in the general population. Due to the low prevalence of such diseases, the road to diagnosis often termed the “diagnostic odyssey”, can last for more than 5 years (1). As a total of 80% of rare diseases have a genetic component (2), the use of Next-Generation Sequencing (NGS) technologies can provide information on the underlying genetic aetiology, resulting in a faster diagnosis and helping patients start treatment programs much more quickly. Uncovering the underlying causes reveals precision medicine treatment options for patients and can be of huge benefit for care standards and symptom management.
Complex diseases are multifactorial and have both genetic and environmental components. The genetic backgrounds of these diseases are often polygenic and do not follow a Mendelian pattern of inheritance. More importantly, many of the mutations responsible are in complex non-coding regions of the genome. Recent developments in NGS technologies have made these regions more accessible for analysis and are accelerating complex disease research.
The field is required.