Individuals with Intellectual Disability of known genetic origin show differences in behavioural characteristics depending on the membership of their gene variant to a group with convergent cellular mechanisms, referred to as a Gene Functional Network (GFN). However, the relationships between GFNs and brain organisation are yet to be explored. I propose using network analyses to examine whether genetic cause, classified by GFN membership, is associated with differences in organisational principles of behaviour, brain function and brain structure. Two GFNs will be examined: those that are direct and indirect modifiers of synaptic physiology, and those that are chromatin structure modifiers.