Cholesterol and autism

One of the doctors that treat my children who have autism suggested something this week that I had not heard of before.  He suggested that as part of their annual blood work that we should have their cholesterol level checked to ensure that it isn't too low.  So I spend some time looking to see if there was any information available on this subject.

As it turns out there is some small amount of research that shows that there might be a relationship between low cholesterol levels and autism in a subset of the population.

The possible link between low cholesterol seems have be an offshoot of research into Smith-Lemli-Opitz syndrome (SLOS) which is a metabolic disorder which renders the body unable to make enough cholesterol  to support normal growth and development.  This is a relatively rare disorder (1 in 20,000 to 40,000) that is characterized by distinctive facial features, small head size (microcephaly), mental retardation or learning disabilities, and behavioral problems.  It is caused by a mutation in the DHCR7 gene on chromosome 11. 

Recent research into SLOS has found that most children with SLOS also have autism.  Based on this finding researchers from Johns Hopkins and Kennedy Krieger Institute decided to look at the issue of whether cholesterol played any role into autism. 

In the first study they looked at group of 100 subjects and found that while none of them had the specific markers for SLOS, 19 of them had very low levels of cholesterol (lower than 100 mg/dl which is below the 5th percentile of for children above the age of 2).  So there could be a group of people with autism who have problems with producing enough cholesterol.

In the second study they looked at whether cholesterol supplements helped autistic symptoms in individuals with SLOS and found that the supplements did indeed help.  The authors concluded that "cholesterol ought to be considered as a helpful treatment approach while awaiting an improved understanding of cholesterol metabolism and ASD" .

Or to summarize, we don't know what is going on but there might be a subset of the population with autism who have issues with producing enough cholesterol and giving extra cholesterol might help.

So what's the big deal with low cholesterol?  As adults we constantly hear that we have to lower our cholesterol (or at least the bad form of it) and how harmful high cholesterol can be but we never hear anything about having too low cholesterol.

I can't find a clear list of exactly what low cholesterol can cause but from what I can gather cholesterol is needed for normal development, plays a role in the development of cell membranes, and helps to form a protective covering for nerve cells (myelin).  Also, if you look at the symptoms of SLOS you can get an idea of what can go wrong - low muscle tone, malformations of internal organs, poor growth, mental retardation, as well as other problems.

So I am going to go out on a limb here and say that having too low of cholesterol isn't a good thing.

There clearly isn't much information available about this subject and the work that has been done is very preliminary and needs to be verified and replicated.  But as a  starting point it isn't bad and as I have pointed out in the past, when attempting to treat something like autism where the science isn't there yet you have to go with the best information available.

It will be interesting to see if my daughters have a low cholesterol level.  I don't have any real expectation that they will but it is certainly possible.  

If they do then it is something that we would want to address independent of the autism - if it helps the symptoms great, if not it would be a problem that would need to be addressed anyway.  If their level is normal then it is one more thing that we can cross off the list.