Question

Given below are two statements:
Statement I: Individuals afflicted with phenylketonuria can metabolize phenylalanine
Statement II: Individuals afflicted with galactosemia can metabolize galactose
In the light of the above statements, choose the most appropriate answer from the options given below

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is correct but Statement II is false
• D. Statement I is incorrect but Statement II is true

Hint:

Inborn Errors of Metabolism:
Phenylketonuria (PKU) = CANNOT metabolize Phenylalanine (Defective PAH).
Galactosemia = CANNOT metabolize Galactose (Defective GALT).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Inborn errors of metabolism: enzymatic genetic lesions block substrate catabolism (phenylalanine hydroxylase defect in PKU; galactose-1-phosphate uridylyltransferase defect in galactosemia).
Key Formula or Approach:
\[ \text{PKU: Defective Phenylalanine Hydroxylase (PAH)} \implies \mathbf{CANNOT} \text{ Metabolize Phenylalanine} \]
\[ \text{Galactosemia: Defective GALT} \implies \mathbf{CANNOT} \text{ Metabolize Galactose} \]

Step 2: Detailed Explanation:
1. Statement I: Phenylketonuria (PKU) is an autosomal recessive inborn error of metabolism caused by mutations in the PAH gene encoding phenylalanine hydroxylase. Affected individuals CANNOT metabolize phenylalanine into tyrosine, causing neurotoxic accumulation of phenylalanine and phenylketones. Hence, Statement I is false.
2. Statement II: Galactosemia is an autosomal recessive disorder caused by deficiency of galactose-1-phosphate uridylyltransferase (GALT). Affected individuals CANNOT metabolize galactose, leading to accumulation of galactose-1-phosphate causing cataracts and liver failure. Hence, Statement II is false.

Step 3: Final Answer:
Hence, Both Statement I and Statement II are false, corresponding to option (B).