Pediatric Newsletter #12: genetic vs environmental causes for autism and more

November 23, 2014  |  General

Here is the latest of my more or less monthly newsletter on pediatric topics. In it I highlight and comment on new research, news stories, or anything else about children’s health that I think will interest parents. If you want to subscribe to it and get it in the form of an email each month there is a sign-up form at the very bottom of my home page.

How much of autism is caused by genetic factors and how much by environmental ones?

Autism is always very much in the news. There is intense controversy about its cause, although the bottom line is that we don’t know. It also appears to be increasing, although we don’t know how much of this is what we call ascertainment bias — finding something more when we look for it more. A big part of the controversy is the relative contributions of genetic vs environmental factors.

recent study from Sweden offers useful information about this. The study was immense, over two million children, far larger than any previous ones.

The bottom line is there appears to be more or less a 50/50 split in the relative contributions of nature and nurture. That is, genetics contributes 50% of the causative factors, environment 50%. This is an important finding. Overall, a child with a sibling with autism has a 10-fold higher chance for getting the disorder than does a child without such a family history. The middle part of the article is dense, but the first part and the conclusions are understandable by non-physicians.

Those laundry detergent pods can be quite dangerous for your toddler

recent study examined how common poisoning or other injuries are from those convenient laundry detergent pods. I have seen one severe case myself, causing breathing problems bad enough to land the child on a mechanical ventilator. This study surveyed poison control centers to find out the extent of the problem. It is not trivial.

Between 2012 and 2013 there were over 17,000 exposures to these things, a 600% increase from the previous year, indicating how popular they have become. I can see why they are popular — I use them myself. It’s a lot easier to toss one of them into the wash than pour out detergent from a bottle.

But that convenience comes at a potential risk. Toddlers put anything and everything into their mouths, and the alluring, brightly colored pods quickly dissolve when wet. The survey revealed that there were over a hundred children who required emergency placement of a breathing tube and one death.

So if you use those convenient items, make extra sure your toddler can’t get at them.

Finally we have vaccines for all strains of the deadly meningococcus

Infections from a bacteria called Neisseria meningitides (aka meningococcus) are horrible and often fatal. I have seen probably 20 children die in my career from this, and at least as many suffer terrible complications, such as loss of arms or legs.  This is the bacteria you have probably read stories in the paper about because it can cause lethal mini-epidemics in schools and any place children and adolescents come together in close contact. The infections come in a couple of varieties: meningitis alone, meningitis with septicemia, or septicemia alone. Of the three, the last is generally the worst, with a high mortality rate and serious aftereffects in survivors.

There are five strains of meningococcus that cause disease. We have had a vaccine for four of them for many years. But one of them, group B, has been difficult to develop an effective vaccine for, and this strain is a common cause of disease. The big news, and it is big, is that we now have a vaccine for group B. Meningococcal vaccine is recommended for adolescents — see your doctor about getting it for your child.

All about caffeine: what is it, where is it, and how does it work?

This one is more for you parents than it is for your children. I ran across an excellent and readable summary of what we know about caffeine. First of all, the stuff is everywhere. It is a brain stimulant that is found in many food and drink products, although the most common sources are coffee, tea, and now energy drinks like Red Bull. Here are some fun facts about it.

  1. 68 million Americans drink 3 cups of coffee per day
  2. 21 million Americans drink more than 6 cups per day
  3. 50% of caffeine users experience unpleasant symptoms when they stop, typically headaches, which can last for a week
  4. 5 grams of it can be fatal, but that is 30-40 cups of coffee

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