A Biomarker for Autism: Accelerated Head Growth?
January 31, 2008 by Kristina Chew, PhD
Filed under Health
Researchers from the University of Washington’s Autism Center have found that autistic children have normal-sized heads at birth, and then have accelerated head growth when they are between six and nine months of age, “a period that precedes the onset of many behaviors that enable physicians to diagnose the developmental disorder,” today’s Science Daily reports. The researchers examined the medical records of 28 boys who had been diagnosed with autism spectrum disorder between the ages of 3 and 4 at the UW Autism Center and eight boys with developmental delay. Approximately 20 percent of the autistic children were found to have macrocephaly (abnormally large head sizes). Further, “this aberrant growth” was found both is present “in children who have the early onset form of autism” and also “those later diagnosed with the regression type of the disorder.” Said Sara Webb, an assistant professor of psychiatry and behavioral sciences who led the research,
“This abnormal or accelerated rate of head circumference growth is a biological marker for autism. It occurs before the onset of behavioral symptoms at 12 months of age such as a child’s failure to respond to their name, a preoccupation with certain objects, not pointing to things, a lack of interest in other people and the absence of babbling.”By itself, head growth is not an indicator of autism……..because kids are going to be getting bigger and development is so variable. However, if you notice it and some of these other symptoms, it is a red flag to seek evaluation.”
I’ve noted before that my own son was born with a big head and that this has continued to be the case for him. Looking back, I’ve realized how out of proportion his head was to the rest of his body, which was all long arms and legs. As a baby, Charlie struggled to hold up his head; when placed on his stomach, he tried for some minutes to roll over, and ended up with his face sunk in the carpet, until we came and rolled him back onto his back. He must have been seven when he learned to put his hands out to break his fall; prior to this, if Charlie stumbled, he inevitably landed on his head.
The UW researchers also plan to further study accelerated head growth in autistic children as part of a study on preventing autism in siblings of autistic children.
I have wondered too if the back of the head is a factor. M has always had a flat head in back. Doctors were always concerned with it. Some said it was from being in a car seat so much in foster care as an infant.
That’s really interesting—-Charlie’s head is a lot bigger on the top, always has been. This is less apparent now as he’s gotten older, but when I look at old photos, I can really see this.
Large head circumference is not specific to autism, in fact, the phenotype is for ADHD. Another example of the failure to use meaningful control groups by autism researchers:
http://www.blackwell-synergy.com/doi/abs/10.1046/j.1365-2788.1999.00211.x
I tend not to think that researchers are so stupid that they don’t think of controls or reference, but it also depends on which controls, generally there is standard deviations associated with this as well, significance testing, etc. etc..
I probably need to look at the paper itself, but a purely anecdotal report is that Eleanor’s head was bigger than the average bear’s prior to birth, at birth, pretty consistently all along, and now. But we all have big heads, so no big surprise.
Is it just me, or does this remind anyone else of phrenology (said in a spirit of idle and friendly inquiry)?
You know, I can just see early human sitting around the fire saying, “Ug, kid that act weird have big head too, ug!”
Ben was always a fat head (actually, a complement, since the brain is made up of fat, mostly) since birth (2+ standard deviations above normal), which the doctor noted and was concerned enough to mention. Ben, too, did not sit up until after the typical milestones had passed, 8 months instead of 6 months, whether from muscle weakness, or just too much to carry….
This is off-topic, but he also had a palsy in his hands that I noticed at age 3. There is a study that notes atypical movement in kids before the first year, and purports to be an indicator of autism. I will look for it and be back if I find it. I think it is just another indicator of neurological difference.
Here it is:
Philip Teitelbaum,*† Osnat Teitelbaum,* Jennifer Nye,* Joshua Fryman,* and Ralph G. Maurer‡
http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=9811912
I found this fascinating because 1) it was so visual (pictures included!!) and 2) I saw so much of Ben in it…
rose
Thanks for that study—–yes, this is making me think of phrenology, and of the developmental pediatrician who did an extensive inventory of Charlie’s facial features when he was 3. And of a study that noted large ear lobes in autistic boys, if I am maybe remembering right (or not).
My big headed boy is NT. Patrick’s head is almost exactly average. I wonder what percentage of ALL children have large heads? How can this be a “marker” if only 20% of the autistic children had overly large heads?
I had trouble sitting, standing and walking too (and anything else physical), way past the ‘milestone’ dates. But I don’t have a big head at all and never used to have one either.
“I tend not to think that researchers are so stupid that they don’t think of controls or reference, but it also depends on which controls, generally there is standard deviations associated with this as well, significance testing, etc. etc..”
The study examined only children who had an ASD diagnosis. The deviations in head circumference are based on known standards taken from the general population. The study had NO controls. Whether they thought of using controls other than the general population statistics is subject to debate.
This is a systematic problem caused by overspecialization. There are many genetic mental retardation syndromes which are linked to autism, for example Fragile X, Tuberous Sclerosis, more recently Down’s Syndrome and chromosome 16 deletions/additions.
The phenotype for all these syndromes is mental retardation with a minority having enough autistic-type behaviors to qualify for an ASD diagnosis.
None of these disorders qualify for an autism phenotype designation.
I have a bit of a bigger head then normal folks. Am I autistic or Special? Hell no. Its who I am, and I will leave it be.
I don’t need a doctor to check me up, nor do I need to get studied.
There are people with small heads too in this world. All you parents stop worrying so much and stop putting you kids on medication.
Yes, it’s amazing how parents can worry!