Before revision: The form of genotype-phenotype maps are typically modular. However, the form of the genotype-phenotype map in human brain connectivity is unknown. A modular mapping could exist, in which distinct sets of genes' coexpression across brain regions is similar to distinct brain regions' functional or structural connectivity, and in which single nucleotide polymorphisms (SNPs) at distinct sets of genes alter distinct brainregions'functional or structural connectivity .
After revision: For much of biology, the manner in which genotype maps to phenotype remains a fundamental mystery. The few maps that are known tend to show modular pleiotropy: sets of phenotypes are determined by distinct sets of genes alter distinct brainregions'functional or structural connectivity .