Advanced Dental Admission Test (ADAT)

What deficiency causes Krabbe's disease?

1. Fructose bisphosphatase deficiency

2. Alpha galactosidase deficiency

3. Hexosaminidase A deficiency

4. Galactocerebrosidase deficiency

The correct answer is: Galactocerebrosidase deficiency

Krabbe's disease is caused by a deficiency in the enzyme galactocerebrosidase. This enzyme is crucial for the metabolism of certain lipids, specifically galactolipids, in the brain. When galactocerebrosidase is deficient, it leads to the accumulation of toxic psychosine levels, which disrupts the function of myelin-producing cells (oligodendrocytes) in the nervous system. The resulting demyelination impairs cognitive and motor functions and can lead to significant neurological deterioration. Understanding the role of this enzyme is essential for diagnosing and studying Krabbe's disease. Other deficiencies listed in the options pertain to different disorders, such as fructose bisphosphatase deficiency, which affects carbohydrate metabolism; alpha-galactosidase deficiency, associated with Fabry disease; and hexosaminidase A deficiency, which causes Tay-Sachs disease. Each of these conditions involves different biochemical pathways and consequently leads to distinct clinical manifestations, further emphasizing the unique nature of Krabbe's disease linked specifically to galactocerebrosidase deficiency.