For some of the more well-characterized genomic disorders, a relationship between CNV genotype and clinical phenotype is beginning to emerge (Brunetti-Pierri et al., 2008; McCarthy et al., 2009). For instance, reciprocal rearrangements of 1q21.1 and 16p11.2 influence neuropsychiatric traits, susceptibility to epilepsy and head size in humans. Furthermore, deletions and duplications of each region have contrasting effects on head size and psychiatric features (McCarthy et al., 2009) (Table 1). While the underlying molecular, cellular, neuroanatomical mechanisms are still unclear, these results suggest that the psychiatric features associated with a mutation might relate to specific effects of the mutation on brain growth.
