 When the structure or production of type III collagen is altered by a mutation in the COL3A1 gene, collagen fibrils cannot be assembled properly in these tissues, and the symptoms of Ehlers-Danlos syndrome result.The tests to verify Sack–Barabas syndrome are biochemical samples such as collagen typing (performed on a skin biopsy sample) or collagen gene mutation testing.There is no cure for Ehlers-Danlos syndrome, so individual problems and symptoms must be evaluated and cared for accordingly.