The diagnosis of a child with a single gene disorder can take on different meanings for different families. It is not uncommon for some families to arrive at a pediatric genetics clinic after months or years of searching for an underlying reason for their child’s symptoms. The fact that, through genetic testing, clinicians can put a name to the collection of differences already noted in the child provides the family access to prognostic information, supportive resources, more accurate reproductive risk counseling, and possible relief from the burden of uncertainty.