On 2 May 2010 at 22:25, Joan Warmbold wrote: > > In a discussion about autism on TIPS a while back, a questions was raised > about the role of genetics and heritability in autism. I recently came > across a compelling but also quite concerning article titled , "Lack of > Positive Heritability Findings in Autism Provides Compelling Evidence to > Shift Priority to More Promising Environmental Factors Research." by Mark > Blaxill, Vice President, Coalition for SafeMinds.
Vice-president Blaxill's article appears not to be published in any journal, peer-reviewed or otherwise, but is available on the web with a date of April 2007. It is identified as a publication of "SafeMinds: Sensible action for ending mercury-induced neurological disorders". See http://tinyurl.com/autism-not-hereditary .According to one web source ( http://tinyurl.com/Blaxill ), Blaxill has no degree in science but an MBA, He is a supporter of the discredited autism researcher Andrew Wakefield, and the discredited hypothesis that vaccination causes autism. His affiliation is with SafeMinds ( http://www.safeminds.org/ ), an organization which supports the discredited hypothesis that autism is caused by mercury poisoning. Blaxill's article is an attempt to cast doubt on the findings of a sophisticated study published in Nature Genetics in 2007 which attempted to locate genes responsible for autism (see http://tinyurl.com/linkage-study ). I suspect that Blaxill's critique has little merit, given his lack of training in molecular genetics and the acknowledged scientific value of research published in such a prestigious journal. However, even if he is right, a failure to locate such genes would not invalidate 50 years of research showing a much higher concordance rate for autism among MZ twins than among DZ, a hallmark of high hereditability. Blaxill recognizes this and makes an unconvincing effort to minimize this finding. In fact, the conclusion that autism has a high degree of heritability is widely acknowledged in scientific studies and reviews and is in no danger of refutation. For example... Freitag CM, Staal W, Klauck SM, Duketis E, Waltes R.. Eur Child Adolesc Psychiatry. 2010 Mar;19(3):169-78. Genetics of autistic disorders: review and clinical implications. "Twin and family studies in autistic disorders (AD) have elucidated a high heritability of AD" Santangelo SL, Tsatsanis K.. Am J Pharmacogenomics. 2005;5(2):71-92. What is known about autism: genes, brain, and behavior. "Autism is a neurodevelopmental disorder of genetic origins, with a heritability of about 90%" Spence SJ.. Semin Pediatr Neurol. 2004 Sep;11(3):196-204. The genetics of autism. "Autism spectrum disorders (ASD) are among the most heritable of all neuropsychiatric disorders". Hallmayer, J. et al. Am J Hum Genet. 2002 Oct;71(4):941-6. Epub 2002 Sep 12. On the twin risk in autism. "Autism is considered by many to be the most strongly genetically influenced multifactorial childhood psychiatric disorder." Bailley, A. et al. Psychol Med. 1995 Jan;25(1):63-77. Autism as a strongly genetic disorder: evidence from a British twin study. "The findings indicate that autism is under a high degree of genetic control ". So I suggest that Joan need not be so concerned. Autism is a field where nutcake theories abound. Stephen -------------------------------------------- Stephen L. Black, Ph.D. Professor of Psychology, Emeritus Bishop's University e-mail: sblack at ubishops.ca 2600 College St. Sherbrooke QC J1M 1Z7 Canada ----------------------------------------------------------------------- --- You are currently subscribed to tips as: [email protected]. To unsubscribe click here: http://fsulist.frostburg.edu/u?id=13090.68da6e6e5325aa33287ff385b70df5d5&n=T&l=tips&o=2400 or send a blank email to leave-2400-13090.68da6e6e5325aa33287ff385b70df...@fsulist.frostburg.edu
