Our Studies: An
Investigation into Autism / PDD
Follow Up Study
Genetics Study
Infant Sibling Study
PET and MRI Study
Follow Up Study
Principal Investigator: Peter Szatmari M.D.
Co-Investigators:
Susan Bryson PhD; Michael Boyle PhD
We would like to extend a special thank-you to all of the adolescents and their families
for their continued participation and support in the follow-up study. This study has
now been running for more than 12 years and, as you know, focuses on the comparison of the
outcome of children with Asperger syndrome to that of children with high-functioning
autism. The recent phase of the study has targeted the prevalence and predictors of
anxiety and mood disorders in adolescents with autism or Asperger syndrome. The
collected data shows that 40% of the children with Asperger syndrome and with autism have
experienced at least one episode of a serious anxiety disorder or a depression within
adolescence. From this, analysis suggests that PDD significantly increases the
proneness to these disorders.
With the above in mind, the follow up study now aims to examine how long the anxiety disorders and depression persist and the cause of the increased risk factors to these individuals. Knowing that children with Asperger syndrome have a greater risk of developing these troubles suggests the better the language, the more likely the teenager to experience anxiety disorder or depression. The project hopes to determine the mechanism behind this, examining family histories and possibilities such as the individual's understanding of social-emotional situations.
.Genetics Study
Principal Investigator:
Peter Szatmari MD
Co-Investigators:
Marshall Jones PhD; Susan Bryson PhD; Lawrence Tuff PhD; Bill Mahoney MD; Giampiero Bartolucci MD
Collaborators:
Lonnie Zwaigenbaum MD; Steve Scherer MD; John Vincent PhD; Andrew Paterson MD; Roberta
Palmour MD; Wendy Roberts MD
The primary goal of the research program is to identify susceptibility genes associated
with autism and other pervasive developmental disorders (PDD) using a combination of
linkage and association analysis. We have enrolled 200 families who have two or more
affected children (multiplex), and also many families who have a single affected child
(simplex). For each family, blood was drawn on the affected individuals, their unaffected
siblings, the parents and the maternal grandparents. DNA samples have been extracted for
over 1 000 individuals from the multiplex and simplex families. Chromosome 7 continues to
be a hot spot for research and the results are promising, but still there is much work to
be done.
The genetics study is also very interested interested in "modifier genes". These gene are not directly responsible for autism, but they may have an affect on clinical expression. Further hopes from understanding modifier genes include understanding the diversity shown among PDD cases. To continue our pursuit of the genetic origin of autism we would very much appreciate the families involved continued participation.
Infant Sibling Study
Principal Investigator:
Lonnie Zwaigenbaum MD; Susan Bryson PhD
Co-Investigators:
Peter Szatmari MD; Isabel Smith PhD; Wendy Roberts MD
Many parents of children with autism spectrum disorders know the frustration of
recognizing their child’s developmental differences from an early age, only to have
these concerns fall on deaf ears. Delays in diagnosis lead to missed opportunities
for early intervention, as well as frustration for parents in search of help for their
children. Parents' recollections and analysis of home videotapes taken prior to diagnosis
have shed some light on which signs of autism may be apparent during the first year. If we
could identify specific features that identify which infants are at the highest risk of
autism, this information could be used to teach health care providers and ensure that
children with autism are diagnosed as early as possible.
The infant sibling study, which now includes over 100 families, looks at the early
development of siblings of children with autism/PDD, who themselves are at higher risk of
the diagnosis. Most siblings develop in an entirely typical fashion, and families
have found it very reassuring to have a detailed assessment to document this. Some
siblings do show some differences in how they communicate, interact and play, relative to
other infants of the same age. We have developed a new observational tool that has helped
us to elicit and thoroughly document these atypical patterns of development. This has
helped us to identify which infants require closer follow-up, and to make suggestions to
families on what may be helpful for building their infants’ skills. So far, we have
found that 1 in 4 of the infant siblings in our study show some indication of difficulty
in early development by the age of 12 months; we have also found that the more early
markers identified means the more likely the child will show increased autistic signs by
the age of two. These markers offer great promise in allowing intervention to begin
earlier than ever before.
[For more on the Infant Sib Study ...]
PET and MRI Study
Principal Investigator: Jeremy Goldberg MD
Co-Investigators:
Claude Nahmias PhD; Peter Szatmari MD;
Lonnie Zwaigenbaum MD.
In our imaging study, we are measuring a number of different aspects of brain function
and brain structure in parents of children with autism. We are also examining high
functioning (HF) adults with autism. Up until now, it has not been possible to
examine brain function and structure in live humans. This project is now able to
investigate serotonin (5HT) function in the relatives of children with autism.
Provisional data shows that brain serotonin receptor density is dimished in 14 of
19 regions sampled in the parent group. The study will soon begin imaging high
functioning adults with autism, hopefully by the end of this year.
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