For each individual with EDS, the clinical story is unique. There isn't a single answer as to why an individual might have features of more than one type of EDS. The first step that they could take to sort this out is to visit a medical geneticist. It is possible that they might benefit from laboratory testing to confirm the molecular or biochemical basis of the form of EDS that they have. Sometimes, but not always, the testing helps to clarify the clinical confusion. It may be, however that they have features of more than one type of EDS because they have a connective tissue disorder that hasn't yet been "described", meaning that the underlying protein abnormality or gene mutation is unknown. Future research studies will be necessary to answer the question. Answered by Melanie Pepin MS, CGC