Rare Disease Day is celebrated on 28 February and aims to spread awareness by events hosted in over 100 countries. There are over 6,000 identified rare diseases affecting over 300 million people worldwide. While most rare diseases are genetic, almost 30% of rare diseases are the result of infections, allergies, and other environmental causes. In Europe, a rare disease is defined as a disease that affects fewer than one in 2,000 people. Awareness of rare diseases is important as they are often misdiagnosed or have a lack of information surrounding them, leading to a delay in diagnosis.

GlobalData’s Epidemiology and Market Size Database covers almost 200 rare diseases, one of which is lupus nephritis. Figure 1 shows the diagnosed prevalent cases of lupus nephritis in the UK in 2021 by class. The classes increase in severity as the class number increases. For example, class I includes minimal mesangial lupus nephritis and class VI includes advanced sclerosis lupus nephritis. Over 60% of diagnosed prevalent cases are seen in class IV and V, which likely means the diagnosis of lupus nephritis is delayed. This could be due to an initial misdiagnosis of the disease, which results in late diagnosis and treatment starting at a more advanced stage of the disease. An increase in awareness would lead to more timely diagnoses in the early stages of the disease, possibly resulting in a better prognosis due to earlier treatment.

Figure 1. Diagnosed Prevalent Cases of Lupus Nephritis in the UK in 2021 by Class.

Source: GlobalData.

Rare diseases are continually being discovered and can result from infections. As such, Covid-19 could play a role in the development of a new rare disease. While the Covid-19 pandemic is still ongoing, it is difficult to predict what residual effects will be seen in populations affected by the virus. However, there have already been reports of “long Covid-19”, where symptoms persist for over three months after a patient is diagnosed with Covid-19. Those with long Covid-19 will need to be monitored and evaluated further to get a better understanding of this disease, which may evolve into a rare disease.

Ahead of Rare Disease Day 2021, it is important to acknowledge that rare diseases affect millions of people worldwide, and increased awareness could lead to more timely diagnoses and treatment, improving the quality of life for those affected.