Publication date: 26 Feb 2023
Rare diseases represent a large group of individual diseases affecting small populations, often with difficult diagnoses and less treatment options than more common diseases. The diseases are grouped together for intellectual convenience. This generalization focuses attention on common health challenges and treatment goals that ultimately aim to improve patient lives. On the other hand, it also creates confusion as the number of recognized rare diseases and the number of people affected varies depending on who is doing the counting. A worldwide Orphanet estimate is that there are about 300 million people affected by one of 6,000 rare diseases, amounting to a 4% prevalence rate. In the U.S., the National Institutes of Health uses a definition that conditions affecting 200,000 or fewer persons in the U.S. are considered to be rare. This results in over 7,000 rare diseases that affect 30 million Americans, or about a 9% prevalence rate. Others have argued that the number of rare diseases is closer to 10,000. Whichever the count, it is clear that millions of people’s lives are affected by rare diseases, and that collectively, rare disorders are not that rare. In that sense, the term “rare diseases” is somewhat of a misnomer and evolves over time. Many rare diseases overlap with other disease categories, such as rare cancers. The numbers and classifications can also change, as some previously common infections have become rare due to widespread vaccination for example. Yet, even with these caveats, chances are we’ll probably all come to know someone dealing with a rare disease in our lifetime. It is in this context that Rare Disease Day, a worldwide annual event held on the last day of February has steadily grown in relevance since its origination by EURODIS (Rare Diseases Europe) in 1983.
Rare Disease Day calls attention to the fact that millions of people have medical conditions and health issues that are of low prevalence, relatively obscure and poorly understood. Most of these conditions are probably unheard of by the general public, and regrettably, by many health care providers. For such conditions, building awareness, expanding knowledge and facilitating communication are important key steps. There is a critical need to fill informational gaps and freely share this with all who need it. Undoubtedly, rare diseases must compete for attention with other diseases for funding, research and therapeutic development. Education is also important to prevent the stigmatization of rare disease patients. The adage that “the squeaky wheel gets the grease” may apply here. Rare Disease Day reminds the broader community that now is time to make some noise.
It is estimated that about 70% of rare diseases are genetic in origin. Genetic variation in our DNA makes each of us (except identical twins) unique. Variations among the 3 billion DNA base pairs in our genome affects the expression of about 25,000 genes that ultimately determine what we are. The seemingly random events that govern genetic variation and reassortment with each generation drive evolution. Changes that take place can be good or bad. In the latter situation, an unfortunate alteration of the DNA– a mutation, can lead to the manifestation of a rare disease such as through disabling the function of a critical gene, disrupting the activity of a key enzyme, or by blockage of an important developmental pathway. This leads to systemic disharmony in the body and the manifestation of disease.
There was a time when those with rare diseases had little choice but to accept their condition as fate. Medical professionals could not determine what they had or recommend beneficial treatments. Skeptics would deny that an underlying disease was even present– believing it to be psychosomatic or otherwise caused by stress. The advent of genomic sequencing technology and the capability to rapidly obtain and analyze patient DNA data has been a game changer. It has become possible to definitively identify genetic alterations that directly contribute to the development of thousands of rare disorders. Diagnosis is no longer just guesswork. Knowledge of the genetic cause of a disease opens the door to scientific understanding and targeted therapies. Thousands of rare conditions so characterized are grounded in the genetic fact of their DNA sequences– the disease correlation is undeniable. The expanded application of sequencing tools to rare diseases is the focus of organizations such as the Rare Genomics Institute.
The increasing optimism that many rare diseases can be explained by the identification of altered DNA sequences is tempered by the fact that many rare disorders are yet to be characterized. For example, it is possible to have a disease that nobody else has ever been documented to have. Some diseases are not readily detectable or treatable now. Do they matter, or does anyone care? Scientifically, every disease datapoint does matter and can contribute to the unraveling of our understanding of rare diseases. Therefore, patients should not remain silent, even though their condition may be extremely rare. First steps must be taken to add new data points if progress is to be made. Scientific knowledge is based on continual observation and experimental verification. Rare diseases can be natural experiments that shed light on disease pathways. Indeed, repetitive observations and associations lead to the recognition of patterns that define all diseases. Knowledge sharing, not just for scientists or medical professionals, but for affected patients and families, opens the door to hope that something can be done to alleviate a condition.
The internet can be an enormous facilitator in bringing knowledge to the forefront and in community building. RareShare seeks to build awareness and promote knowledge sharing in its over 1,000 dedicated rare disease communities. The job is enormous and progress can be slow. However, it is important to recognize that with new scientific understanding, substantive improvements in therapies for specific rare conditions are continually being made. Ultimately, there may be a snowball effect– progress keeps expanding as more join and add their piece to the puzzle. RareShare as a platform is open to all recognized rare diseases– if a community doesn’t exist, we can also create one. It depends on the active involvement of its members in telling their stories, sharing knowledge, learning from others and working towards improved outcomes. As a non-profit entity, our service is free of charge, we do not sell member information or advertisements, and we are staffed entirely by unpaid volunteers. Our funding comes through donations and grants. In support of Rare Disease Day, RareShare provides a pathway for engagement for those interested in rare diseases, including patients, families, care givers, medical professionals, researchers and disease advocates. Join us.