Question

Galactosemia is due to deficiency of which enzymes

• A. Galactose-1-phosphate uridyltransferase
• B. HGPRT
• C. Galactokinase
• D. Epimerase

Answer 1

The Correct Option is A

Galactosemia is a metabolic disorder that primarily arises from the deficiency of specific enzymes involved in the metabolism of galactose, a type of sugar. This condition leads to an accumulation of galactose or its metabolites in the blood, which can result in various health issues, especially in infants.

The enzyme deficiency at the core of classical galactosemia is Galactose-1-phosphate uridyltransferase (GALT). This enzyme plays a critical role in the conversion pathway of galactose into glucose, enabling its proper utilization and excretion by the body. When GALT is deficient, galactose-1-phosphate accumulates in the liver and other tissues, causing toxic effects and symptoms commonly associated with galactosemia.

Other enzymes associated with galactose metabolism are:

• Galactokinase: Deficiency leads to a less severe form of galactosemia, primarily causing cataracts due to the accumulation of galactitol.
• Epimerase: Deficiency can also cause galactosemia, but it is rare and can vary in severity depending on the specific epimerase defect.

The incorrect options in this context are:

• HGPRT: Not related to galactose metabolism; it is involved in purine metabolism.

Thus, the deficiency of Galactose-1-phosphate uridyltransferase is the primary cause of classical galactosemia.