ABNORMALITIES IN THE PRODUCTION OF EXTRACELLULAR MATRIX BY CELLS FROM INDIVIDUALS WITH INHERITED DISORDERS OF COLLAGEN BIOSYNTHESIS**Supported in part by grants from the USPHS (AM 21557, AM 30426, GM 07266), Clinical Research Grants from the March of Dimes Birth Defects Foundation (6-298 and 6-312), a grant from the Osteogenesis Imperfecta Foundation, and a scholarship grant from the Poncin Fund. PHB is an Established Investigator of the American Heart Association; GSB is a predoctoral trainee of the Medical Scientist Training Program at the University of Washington (GM 07266); DWR is the recipient of a Research Career Development Award (HD 00330).