 The "MTTP" gene provides instructions for making a protein called microsomal triglyceride transfer protein, which is essential for creating beta-lipoproteins.These lipoproteins are both necessary for the absorption of fats, cholesterol, and fat-soluble vitamins from the diet and necessary for the efficient transport of these substances in the bloodstream.Most of the mutations in this gene lead to the production of an abnormally short microsomal triglyceride transfer protein, which prevents the normal creation of beta-lipoproteins in the body.