phenotype into its various clinical subtypes allows recognition of patterns of causation (pathways and interacting proteins) that would not be possible if disorders were simply named after the genes that cause them. An illustration of the different types of Ehlers-Danlos syndrome (EDS) (Figure 3B) is an elegant example of this. Interestingly, varying components of complement 1 cause periodontal EDS while a zinc transporter and components of the O-linked glycosylation pathway cause the spondyloplastic form of EDS. The hypermobile type has not yet yielded to intense molecular interrogation, suggesting that it might be an oligogenic or multifactorial disorder.
