The majority encode enzymes (including those modifying collagen) or structural proteins (18 collagen genes) with regulatory products (signal, membrane channel, receptor, transcription factors) are well-represented in Figure 2B. Of great interest are the 31 of the 37 genes in the mitochondrial genome that are altered in EDS patients, which are likely acting similarly to the nuclear DNA polymerase gamma (POLG) gene changes in 17 patients to deplete the mitochondria and their energy supply to the nerve and muscle (see Section 4). Here, POLG is linked to Ehlers-Danlos syndrome.