Is Shwachman-Diamond Syndrome concidered an inborn error of metabolism?

My son has Shwachman-Diamond syndrome. His does not make ANY pancreatic enzymes needed to break down food. Our insurance company is telling us that his syndrome is not concidered an inborn error of metabolism, but some doctors are telling us that it is. I would really like any feedback on this matter.|||Well.... Shwachman-Diamond Syndrome is a rare genetic disorder . It affects many organs in the body . Not only the pancreas also bone marrow problems , skeletal abnormalities and short stature . Inborn error of metabolism comprise a large class of genetic diseases involving disorders of metabolism .The majority are due to defects of single genes . Inborn errors of metabolism are now referred to as congenital metabolic diseases or inherited metabolic diseases . Hope this information helps .