Lysosomal Storage Diseases

Think about it for a second, what do lysosomes do? Lysosome is a cell organelle containing enzymes that break down proteins and other large molecules into smaller constituents and that disintegrate the cell itself after its death. During infection, say a bacterial infection, bacteria are engulfed by macrophages (immune system cells). These immune system cells digest they bacteria using lysosomal enzymes. Without these powerful enzymes, you would essentially have a defective immune system.

There are a number of lysosomal storage diseases that are caused by the malfunction of the lysosomes or one of their digestive proteins; examples include Tay-Sachs disease and Pompe's disease. These diseases are caused by a defective or missing digestive protein, which leads to the accumulation of substrates within the cell, impairing metabolism.

Problems with the immune system, inability to break down certain substances leading to accumulation of the compounds within the cell.

in more primitive animals that count on intracellular digestion ( cnidarians, platyhelminthes ) i assume such a defection would cause starvation of the organism.