Paediatric genetics is increasingly playing a role in explorations of why a child may not be reaching developmental milestones, while experiencing various health concerns and displaying unusual physical characteristics. The diagnostic processes include close analyses of a child's body in order to identify ‘clues’ to possible genetic variation. When the genetic variation identified is new and complex there is significant uncertainty about what relationship that variation has to childhood development and what it will mean for a child's future. This paper, drawing from an ethnographic study of a genetics clinic, explores what versions of childhood difference and normality are produced by genetic explorations marked by uncertainty. The focus is on the significance of visual dynamics within the consultation, in family stories or photographs, and in the images found on websites which catalogue genetic syndromes. Our argument is that inside and outside the clinic the visual interpretations create understandings of the child that at times position him or her as ‘other’, while at other times recognise the child as normal and ‘one of us’. The uncertainty embedded in identifying rare genetic variations enables multiple interpretations to emerge which do not ‘fix’ the child into the category of the ‘genetically other’.