If you have four or even more siblings, then you should get your brain scanned. A study has found that the number of your brothers or sisters, especially younger ones, can trigger the chances of developing a brain tumor.
The study, which was conducted by a team of boffins led by Andrea Altieri with the German Cancer Research Centre in Germany, was a population-based study. The study analyzed 13,613 brain tumor cases in Sweden. The researchers found that people with four or more siblings were twice as likely to develop a brain tumor, when compared with people who had no siblings.
The study also found that there was a two to four-fold increase in brain tumor rates among children who were younger than 15 years and had three or more younger siblings, compared to children of the same age who had no siblings.
However, the study did not find an association between the number of older siblings and brain tumors. The study has been published in the December 12, 2006 of Neurology.
According to the author of the study Andrea Altieri, the study suggested that infectious agents may just be the reason behind the disease. “Since the size of the family and the number of younger siblings correlate with the incidence of brain tumors, this suggests infectious agents may be causing the disease, “said Altieri.
“The number of siblings a person has indicates they were exposed at an early age to infections, since children come in close contact with each other and thereby share exposures to many infectious agents,” added Altieri.
The finding that brain tumor rates were higher among people with younger siblings, and not older siblings, also prompted the researchers to suggest that infections or re-infections in late childhood may play an important role in causing the disease, while exposure to infection sin infancy, birth to five months old.