Q. Both my little grandsons have been diagnosed with autism. I’m certain it was because they received immunizations as babies but someone recently told me that might not be true. What do you think?
A. Linking immunizations to a variety of illnesses or conditions has been quite popular. Unanswered questions include whether or not the individual already had some inflammatory process going on in brain or body or if the immunization might have functioned as a co-factor to surface an already underlying (although perhaps dormant) condition or none of those. Just this year The New York Times reported on an article published in the Lancet, a British Medical Journal, that provided some interesting results based on examination of genetic data from more than 60,000 people worldwide. Researchers identified common genetic risk factors linking five diagnoses [schizophrenia, bipolar disorders, major depression, attention deficit hyperactivity disorder or ADHD, and autism], which pointed to a specific signaling system. According to Dr. Jordan Smoller, lead author of the paper and a professor of psychiatry at Harvard Medical School and Massachusetts General Hospital: “What we identified here is probably just the tip of an iceberg. As these studies grow we expect to find additional genes that might overlap.”
Which disease, if any, develops is thought to depend on other genetic or epigenetic (environmental) factors. Sometimes one individual with a genetic mutation developed one condition, a relative with the same mutation might develop a different one. Reportedly the researchers had already seen some clues of overlapping genetic effects in identical twins. One might have schizophrenia while the other had bipolar disorder, meaning that two different diagnoses may have the same genetic risk factors. This could help explain the reason that some of these diagnoses seem to cluster in families.