Babies with tay-sachs disease cannot be treated by injecting the missing enzyme into their blood because

Babies with tay-sachs disease cannot be treated by injecting the missing enzyme into their blood because the enzyme function is not in the blood it is only in lysosomes.
Actually tay-Sachs disease is very rare and mostly it comes from parents to child. In this disease the nervous system is destroyed because their is too much fat build in the brain. There is no cure for this disease.

Glucose, also called grape sugar, blood sugar or corn sugar, is among the simplest and one of the primary naturally occurring sugars. produced naturally by plants as the primary photosynthesis product, it is heavily used by living beings as a main energy source and is necessary for cellular respiration. chemically, it is a monosaccharide carbohydrate and serves as a building block for complex sugars like starch.