30 Oct Autism and Language Impairment: Possible Common Genetic Link
MedicalResearch.com: What are the main findings of the study?
Dr. Brzustowicz: The objective of this study was to search for locations in the human genome that impact language ability in individuals with autism as well as in their family members without autism. To do this, we recruited families with an individual with autism and at least one other family member without autism but with a language learning impairment. We identified two locations in the human genome that are linked to language ability in these families. Importantly, these locations do not appear to be specific to language impairment in the individuals with autism, but are related to language ability in other family members as well. This suggests that while individuals with autism may have new, or de novo, genetic variations that are important for risk of illness, they may also carry inherited genetic variation that influence the expression of their illness. The effects of these inherited variants can also be seen in the language performance of family members without autism.
MedicalResearch.com: Were any of the findings unexpected?
Dr. Brzustowicz: Although we did not select these families for other members with impairments in social responsiveness or for the presence of obsessive or compulsive thought or behaviors, we were able to identify several additional locations in the genome that were linked to these traits. This means that this one study has identified regions in the genome that are linked to all three of the behavioral domains that are commonly impaired in autism. Furthermore, we have identified these regions as being related to the expression of milder, but related, behavioral traits in family members without autism.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Brzustowicz: While much of the recent work on the genetics of autism has focused on de novo variants that appear to be involved in risk of illness, our study reaffirms that there are also important inherited genetic factors that are involved. Understanding the relative contributions of de novo and inherited risk factors in the population and in specific families is very important for clinicians to be able to provide accurate risk assessments for future pregnancies in families with one child with autism. We are also hopeful that this and other genetic studies will further inform us about the biology of autism, potentially providing new insights that may help in the development of new treatments.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. Brzustowicz: Our study identified regions of the genome that are linked to these various components of autism, but did not identify the specific genes that are involved. We are currently sequencing DNA from individuals in our study as a method to identify the specific genes and variants that are involved in increasing risk. It will also be important to replicate this work in additional families. Our group is currently recruiting new families from New Jersey and surrounding regions to participate in such a replication study. Any family who might be interested in participating can visit our study website http://njlags.dls.rutgers.edu/ for more information about how to get involved with our research.
Christopher W. Bartlett, Ph.D., Liping Hou, Ph.D., Judy F. Flax, Ph.D., Abby Hare, B.S., Soo Yeon Cheong, Ph.D., Zena Fermano, M.A., Barbie Zimmerman-Bier, M.D., Charles Cartwright, M.D., Marco A. Azaro, Ph.D., Steven Buyske, Ph.D., Linda M. Brzustowicz, M.D.