The earlier an autism diagnosis is made, the earlier treatment and intervention can begin. With no medical test to rule out autism, clinicians make a diagnosis based on observation of a child’s behavior. Often, the diagnosis is not made until a child is around age 3.
Research led by Harvey J. Kliman, M.D., research scientist in the Department of Obstetrics, Gynecology & Reproductive Sciences at the Yale School of Medicine and reported in the June 26, 2006, online issue of “Biological Psychiatry” is shedding light on pathologic findings in the placentas of children with autism spectrum disorder (ASD).
The research group designed a study to determine if the presence of trophoblast inclusions in the placenta, a placental abnormality, is a marker for ASD. The researchers, using microscopic examinations of placental tissues, discovered that the placentas from ASD children were three times more likely to have these inclusions.
Kilman reports that “We knew that trophoblast inclusions were increased in cases of chromosome abnormalities and genetic diseases, but we had no idea whether they would be significantly increased in cases of ASD. These results are consistent with studies by others who have shown that ASD has a clear genetic basis.”
Trophoblast inclusions appear to be the result of abnormal cell growth in the placenta. Kliman offers the analogy of these inclusions as akin to a check-engine light on a car’s dashboard: “When the light goes on it simply means that something is not right. If the light is on and there is, for example, steam coming from under the hood, then it is likely that the radiator is leaking. However, if the check engine light is on and there is nothing obviously wrong, then the car should be carefully checked.”
Larger studies are in the works; the Yale team plans to examine the placentas in greater detail. They will examine the placentas of the children in the study in greater detail to gain insight into the biological basis of the inclusions in ASD.
Fred R. Volkmar of the Yale Child Study Center states that “If the work is confirmed by the next series of studies, then the finding of trophoblast inclusions at the time of birth in the absence of any obvious genetic abnormalities would be an indication to have a child examined by a specialist to determine the presence of ASD.”
While initial screening for ASD may be performed by a child’s pediatrician, additional screening and diagnoses are generally done by a specialist. The earlier a diagnosis is made, the earlier treatment and interventions can begin. The study of these placental abnormalities may lead to earlier diagnoses.