Dr. Joseph Buxbaum is the Director of the Seaver Autism Center. Dr. Buxbaum discusses the SHANK3 gene, which helps synapses to properly function. Around 1% of children with ASD have SHANK3 mutations, making it one of the most common single-gene causes of autism. Dr. Buxbaum also discusses Insulin-like Growth Factor (IGF1), which is the second drug aimed at treating core symptoms of autism, and is currently being tested on humans.
If it’s effective, I’d like to try it
We can hope that this treatment may be effective in treating the consequences of mutations in the SHANK3 gene. The 22q13.3 region harbors the SHANK3 gene which is lost in the 22q13.3 deletion syndrome also known as the Phelan-McDermid syndrome. Most cases of 22q13.3 deletion syndrome are not inherited and are caused by reproductive errors (sperm or egg).
http://ghr.nlm.nih.gov/condition/22q133-deletion-syndrome
Climate change scientists have proven beyond doubt that climate change is occurring and that human activity contributes to climate change. Climate change scientists have yet to put a human face on the consequences of planetary environmental degradation. What is less known and poorly understood is that evolutionary biologists are becoming increasingly concerned that planetary environment degradation may be damaging the human genome itself. There are a few autism research groups that are examining the neurotoxic effects of environmental pathogens in the womb or in newborns (CHARGE, MARBLES, SEED). These important studies are not examining the frequency and possible causes of reproductive errors that occur prior to conception.
An important study was published a few months ago (Nov 2011)) that examined the frequency of de novo sperm mutations in workers at a benzene manufacturing plant in China. The study recruited 30 workers who had worked at the benzene manufacturing plant for more than a year and divided the workers into three groups, a low exposure group, a moderate exposure group and a high exposure group. The study included a control group of 11 unexposed workers from the same town.
Every participant in all four groups was found to have de novo sperm mutations including 1p36 sperm mutations. The frequency of the 1p36 sperm mutations was lowest, but present, in all volunteers in the unexposed group, higher in the low exposed group, higher still in the moderate exposed group and highest of all in the high exposed group. The 1p36 deletion syndrome is present in 1 in 5,000 to 10,000 newborns:
http://ghr.nlm.nih.gov/condition/1p36-deletion-syndrome
The 1p36 deletion syndrome is also associated with co-occurring autism:
http://174.79.186.155/GeneDetail/MTHFR
This is the first study that has demonstrated a direct connection between a specific de novo sperm mutation (1p36 deletion), a specific severe genetic syndrome (1p36 deletion syndrome) and a specific environmental pathogen (benzene). Benzene, because of its high octane number, is an important component in the production of refined gasoline and diesel fuels. The Chinese sperm study is so well designed that it appears to be bullet proofed against the inevitable skepticism from climate change deniers, anti-science Republican politicians and the American Petroleum Institute’s stable of hired gun so-called experts.
The CHARGE group published a study a year ago that found that living in close proximity (<309m) to heavily congested freeways in California was associated with increased risk for autism. Benzene, because of its high octane number, is an important component in the production of refined gasoline and diesel fuels and one has to consider the possibility that at least some of these cases might be related to de novo sperm mutations associated with long-lasting high exposure to benzene particles and other air borne environmental pathogens.
The SFARI Autism group recently published an article that found that new (de novo) mutations can accumulate in the sperm of men as they age increasing the risk of autism in their daughters, when there is no family history of the disorder.
The evidence from evolutionary biology suggests that all males generate sperm mutations throughout their lives and the frequency of de novo sperm mutations increases with advancing age. What is not known is if the frequency of de novo sperm mutations has increased over several generations You can follow this discussion and comments with many references that should interest climate change activists if not autism researchers at :
http://sfari.org/news-and-opinion/news/2012/effect-of-paternal-age-seen-in-girls-with-autism
The rapidly advancing technology (FISH) fluorescence in situ hybridization has allowed researchers to examine the frequency and types of de novo sperm mutations in healthy male donors. A male in a single donation creates tens of thousands of sperms which now can be directly examined using FISH assays. This technology cannot be used to measure the frequency and types of de novo egg mutations for obvious reasons.