Sodium dodecyl sulfate-PolyAcrylamide Gel Electrophoresis (SDS-PAGE) analysis of collagens secretion in a patient affected with vascular EDS and a control. The band corresponding to type III collagen is indicated by α 1(III). Columns 1 and 3 correspond to the supernatant culture medium of the cutaneous fibroblasts. Colums 2 and 4 correspond to cell extracts. Secretion of type III collagen in the medium is reduced in the patient (column 1) as compared to the control (column 3). Conversely, there is intracellular retention of abnormal collagen in the cell extracts of the patient (column 2) as compared to the control. In addition, the mutant collagen III has a higher molecular weight due to additional post-translational modification α 1(III)M.