03/01/2012 05:58 pm ET | Updated May 01, 2012

To Be Rare Or to Be Neglected: For a Disease, That Is the Question

Could holding annual Rare Disease Day on the 29th of February possibly be a wry statement on just how rare these diseases are? Other diseases might decadently have their annual day every year, but rare diseases are so very rare that even their annual day is occasional? The idea appealed to me -- I rather hoped it was so. Their website, which is disappointingly lacking in this sort of detail, fails to specify, but it does state that this is the fifth Rare Disease Day since 2008, so I have a hunch that leap year wit is, alas, not part of their campaign. Alas.

According to the Rare Disease Day website information, from a U.S. perspective, a rare disease is one that affects less than 200,000 Americans at any given time. Somewhere between 6,000 to 8,000 of these diseases exist, most of them affect children, most of them are genetic, and most of them are so rare that they haven't been bombarded with of the massive donations, political will, eager scientists, or motivated pharmaceutical companies that higher profile diseases like HIV/AIDS, tuberculosis, or cancer attract.

But is it worse to be designated rare or neglected? More than one-sixth of people in the world have so-called Neglected Tropical Diseases, or NTDs, as we who love an abbreviation like to call them. These infections would feature in starring roles in Rare Disease Day if you were only counting people in high income countries. Unfortunately, NTDs are not at all rare in many parts of Africa, Asia and Latin America. I spent yesterday morning at a really interesting Center for Strategic and International Studies event on the call to fight NTDs and it started me thinking about the two groups of diseases.

Rare diseases and NTDs tend to share a predilection for names that are difficult to pronounce, low profit potential for drug manufacturers, lack of perceived disease "sexiness," low likelihood that people in rich countries will be at risk, and a fundraising challenge for NGOs who run mass charity walks where people are sponsored in memory of family and friends who have been affected by a specific disease.

The two disease categories differ in that advocates for rare diseases tend to focus on trying to attract funds that will induce and enable scientists to find a cure, while for many NTDs, scientists have often already found the cure. In fact, they've often found prevention methods too. And they are usually highly cost effective. So, unlike rare diseases, a huge chunk of the funds NTD advocates seek for NTDs are not to fund the science, but rather to enable people to gain access to the often cheap and effective cures and prevention that they need and that scientists identified long ago.

In terms of the science, it seems that "rare diseases" are more likely to be neglected than so-called "neglected tropical diseases."

Perhaps in terms of NTDs, it's not the diseases but the people who have been neglected? And they don't even get a designated day.

For more by Dr. Layla McCay, click here.

For more health news, click here.