It is interesting to consider that, while rs4141463 falls in a MACROD2 intron, the precise location could be irrelevant to its possible functional impact on ASD risk. Recent evidence (30), yet to be corroborated, suggests that this SNP or one of many correlated SNPs in this region (Fig. 1) acts to regulate expression of PLD2. The observation becomes more noteworthy in light of the fact that our exploratory analyses also identify PLD5 as another locus possibly associated with autism. PLD proteins could play an important role in risk for autism. The protein derived from PLD2 has been shown to regulate axonal outgrowth (31) and metabotropic glutamate receptor signaling (32).
