A very important paper was published this week in Nature (Pinto et al., 2010; http://www.nature.com/nature/journal/vaop/ncurrent/full/nature09146.html). In this paper it was reported that persons with an ASD diagnosis were found to "carry a higher global burden of ...CNVs..." So what are those CNVs? They must be some substance carried in vaccines! Finally we found the environmental toxin that Big Pharma has used to cause the autism epidemic. Well, not so much. CNVs are copy number variants and this refers to pieces of DNA in which there are duplications or deletions of segments of a chromosome. We typically have two copies of every gene sequence but sometimes there are more (or fewer). So duplication of a gene can be inherited and additional duplication can occur during the unzipping/rezipping of the DNA that occurs during replication. Deletions and translocations of gene segments can occur as well.
CNVs specifically refer to when there is a difference in the number of gene sequences across persons/populations. In this study, the investigators found that persons with a diagnosis of an ASD were more likely to have CNVs than the matched control group. The study also looked at the genetic material of the parents of the persons with ASDs and found that some of the CNVs were inherited while some of them were novel events presumably occuring during replication. The total number of CNVs identified was just under 450 with the type of CNV somewhat equally split across these mechanisms. Though this number is quite large and continues to support the notion that the genetics of autism is quite complex, this study also sought to determine what each of these genes were involved in.