Krabbe disease is described as a deficiency of which enzyme?

• A. Beta-glucosidase
• B. Alpha-galactosidase
• C. Beta-galactosidase
• D. Hexosaminidase-A

Answer: (A)

Krabbe disease is a lysosomal storage disorder caused by a deficiency of galactocerebrosidase, also known as GALC. When GALC is deficient, the breakdown of certain galactolipids is impaired, leading to the buildup of psychosine, a toxic byproduct that damages myelin-producing cells in the central and peripheral nervous systems. This demyelination produces the severe neurological symptoms seen in affected infants, such as irritability, poor muscle tone, feeding difficulties, and developmental delay.

The other enzymes listed are linked to different diseases: beta-glucosidase deficiency causes Gaucher disease; alpha-galactosidase deficiency causes Fabry disease; beta-galactosidase deficiency causes GM1 gangliosidosis (and Morquio B); and Hexosaminidase A deficiency causes Tay-Sachs disease. Krabbe disease is specifically due to GALC deficiency, not any of these.