June 19th, 2009

While HealthPoint strives to round up all the latest and most important PA-related healthcare news, in doing so, we come across some pretty interesting articles related to the medical community.  So from now on, we’ll be sharing one not necessarily Pennsylvania-related–but still interesting and relevant– unique article each day.

To launch the new feature, today we’re asking “Did you know… the truth about allergies?”

Reports the New York Times, in an article exploring the claim that allergy problems run in families:

It is well known that traits like hair and eye color, height and even certain aspects of personality can be inherited. What about allergies?

Environment may get most of the blame, but scientists have found that allergies like asthma and hay fever have a powerful genetic component — just not in the classic Mendelian pattern.

Unlike hair and eye color, they stem from the interactions of a multitude of genes, some conferring protection and others contributing to the development of allergies. As a result, people may not inherit their parents’ specific allergies to ragweed or pollen, but will have an increased likelihood of developing an allergy in general, particularly when both parents have one.

One study of 344 families, for example, found that when neither parent had a history of asthma, only 6 percent of children went on to develop it. But in families where one parent had the condition, 20 percent of children had the diagnosis; in families where both parents had it, 60 percent of children had it too.

More compelling evidence comes from dozens of studies on twins. Generally, when one identical twin suffers from hay fever, asthma or eczema, the other twin has it in 50 to 80 percent of cases. In fraternal twins, the percentage drops to about 25 to 40 percent.

THE BOTTOM LINE

Environment and genetics both contribute to allergies, but studies suggest that genes play a critical role.