Copy-number variations (CNVs) are losses or gains of genetic material, such as a deletion or duplication of a chromosomal region. There is growing evidence that CNVs play a major role in causing autism spectrum disorders and other brain disorders. Christa Lese Martin and her colleagues at Emory University in Baltimore, along with David Ledbetter at Geisinger Health System, propose to map the genes linked to autism and schizophrenia.
In 2011, the researchers reported a 1.4-megabase deletion in the chromosomal region 17q12. This region is associated with autism and schizophrenia, which are both considered to be disorders of brain development. It includes 15 genes, one or more of which may cause the clinical features observed in individuals with this CNV.
In this study, the researchers plan to identify which of these genes cause autism spectrum disorders and schizophrenia by using two different methods. They plan to perform DNA sequence analysis of the 15 genes to find changes in the sequence of each gene individually, and conduct high-resolution studies of CNVs in each gene in the region to look for deletions or duplications involving only a single gene or part of the gene.
The proposed study focuses on individuals who have a large head size and autism, since these clinical features are most often observed in individuals with 17q12 deletions. The researchers also plan to examine the clinical features of individuals with 17q12 deletions to assess how these people are similar to one another.
The identification of a gene associated with autism from this region would allow further detailed studies to help researchers understand how the gene causes the disorder, which may lead to therapeutic targets for treatment.