Genetics: Autism samples show altered gene expression in blood
The results suggest that reduced levels of certain autism-associated proteins could lead to a higher risk of the disorder.
Several studies in the past few years have associated mutations or genetic variants in a play a role at the synapse, the junction between neurons.of candidate proteins with a higher risk of autism. Several of these proteins, including SHANK3 and NLGN3,
Because the expression of many genes varies significantly based on cell type, researchers prefer to analyze gene expression differences for disorders such as autism in neurons from postmortem brain tissue. Postmortem brains are rare, however, and messenger RNA, which codes for protein, can degrade easily in dead cells.
However, some studies have shown that the blood of individuals with autism shows gene expression patterns that are distinct from those of controls.
The new study compared the levels of messenger RNA for SHANK3 and NLGN3 in blood cells of 35 individuals with autism and 35 controls. Individuals with autism have on average 30 percent fewer copies of the RNA message for NLGN3 and 40 percent fewer copies of the message for SHANK3 compared with controls, the study found. By contrast, there is no difference in the levels between 45 individuals with schizophrenia and 45 matched controls.
Yasuda Y. et al. Mol. Autism 2, 9 (2011) PubMed