Genetics and SPD
Have you wondered whether sensory processing disorder is inherited?
Does it run in families?
David Pauls, PhD, a genetics researcher in the department of psychiatry at Harvard Medical School tackled those questions in another standing-room-only keynote address Saturday morning at the SPD Foundation international symposium at the Hyatt in Boston.
The answer seems to be yes and no, he says. That's because genetics involves several types of "connections."
"It’s quite clear that there won’t be a single gene connected with this condition," he told his audience of practitioners and educators. “[But] there is evidence is that this is familial. “There are probably some underlying genetic factors that are contributing to these behaviors.”
The factors that indicate this have been consistent in several studies done recently using parent-interview measurements across related and non-related groups of children. I will update these studies in ADVANCE's Vision Watch department in print shortly. Correlation factors ran between .14 and .17, statistically significant findings. One showed inheritability to be possibly as high as 40 percent.
Pauls recommends further "association" studies that are family-based to collect more information on this. Though in family studies you cannot distinguish between genetic and non-genetic factors, by looking at distribution of DNA in child and parents, you can see which genes did and did not get transmitted. If you then look at a series of kids with sensory problems, you can compare how many have had the same things transmitted and then compare what the genetic profile is to the sensory behavior.
This is cheaper, he said, than doing case/control studies that require huge numbers of subjects and can be cost-prohibitive.
The important task, in order to establish sensory defensiveness as a differential diagnosis, is to look for it in people who have no other psychopathology. That has been difficult to prove. It is often associated with Tourette's syndrome, ASD, ADHD and OCD. But Pauls says that there are high-end cases of over-responsiveness that stand alone, without any comorbidities.
So, should sensory defensiveness be added to the DSM-V, the mental and behavioral health manual that lists diagnoses in that field? Yes, says Pauls. "Research shows there are people with pretty extreme behaviors with no other psychiatric diagnoses, and we don’t know at this point what is causing them. There is a significant underlying biological deficit. They would benefit from intervention."