"Because the gene alterations that we found influence brain development, our hope is that they may eventually provide clues to developing diagnostic tests as well as treatments for children with autism," said co-author and lead clinician Josephine Elia, M.D., a child psychiatrist at Children's Hospital.
Unlike changes to single bases in DNA, called single-nucleotide polymorphisms (SNPs or "snips"), CNVs are larger alterations in DNA structuremissing or repeated stretches of dozens or hundreds of bases in sequence. CNVs have been implicated in other neuropsychiatric disorders, such as schizophrenia, bipolar disorder and attention-deficit hyperactivity disorder (ADHD)the latter in a previous study by White and Elia.
In the current research, White and colleagues searched for CNVs in a discovery cohort of 631 children with autism, 1,162 parents of these children, and a healthy control set of 1,775 children. They found nearly 400 inherited CNVs in autism subjects that did not occur in controls. They also analyzed a second cohort of 593 additional autism subjects, 1,109 corresponding parents, and 2,026 healthy controls. This second study found another set of nearly 400 inherited CNVs exclusive to children with autism. Surprisingly, no single gene was frequently disrupted in either set, and only a few genes harbored CNVs in both sets.
Although there was relatively little overlap between sets of CNVs found in the two cohorts, the CNVs tended to occur in genes that affected biological processes relevant to autism. "While individually, CNVs are rare, each of them often appearing only in one family in our study, we found in this study that CNVs tend to occur in genes with similar functional rol
|Contact: John Ascenzi|
Children's Hospital of Philadelphia