Question

Krabbe's disease is caused by which enzyme deficiency?

• A. Deficiency of beta-galactosylceramidase
• B. Deficiency of aryl sulphatase
• C. Alpha galactosidase
• D. Acid lipase

Hint:

Globoid cell leukodystrophy and the GALC gene.

Answer 1

The Correct Option is A

Step 1: The question maps a leukodystrophy to its missing enzyme. Krabbe disease is the globoid cell leukodystrophy and is inherited in an autosomal recessive pattern. Step 2: The defective gene is GALC at locus 14q31, and the protein it encodes is galactosylceramidase, also written as beta-galactocerebrosidase. Without it, galactocerebroside processing fails. Step 3: The toxic metabolite psychosine builds up, destroys myelin forming cells, and recruits the multinucleated globoid macrophages that name the disease. Step 4: Each distractor belongs to a different storage disease: aryl sulphatase A to metachromatic leukodystrophy, alpha galactosidase to Fabry, acid lipase to Wolman. So only beta-galactosylceramidase fits Krabbe. \[\boxed{\text{Deficiency of beta-galactosylceramidase}}\]