Question:medium
NARP syndrome is seen in which type of disorder?
NARP syndrome is seen in which type of disorder?
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Neuropathy, Ataxia, Retinitis Pigmentosa from an MT-ATP6 mutation points to one organelle.
Updated On: Jun 24, 2026
- Mitochondrial function disorder
- Glycogen storage disorder
- Lysosomal storage disorder
- Lipid storage disorder
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The Correct Option is A
Solution and Explanation
Decode the acronym first: NARP means Neuropathy, Ataxia and Retinitis Pigmentosa, a triad pointing to a defect in cellular energy generation.
The molecular cause is a point mutation in mitochondrial DNA, the m.8993T>G change in MT-ATP6, which disrupts a subunit of ATP synthase (complex V) and therefore cripples oxidative phosphorylation. Since the gene sits in the mitochondrial genome, the disease is transmitted maternally, and a heavier burden of the identical mutation tips the phenotype into maternally inherited Leigh syndrome, both facts confirming its mitochondrial nature.
None of the storage-disease categories fit: glycogen storage diseases, lysosomal storage diseases and lipid storage diseases each stem from specific enzyme deficiencies in carbohydrate, lysosomal or lipid metabolism rather than from a failure of the respiratory chain.
Hence NARP belongs to the mitochondrial functional disorders.
\[\boxed{\text{Mitochondrial function disorder}}\]
The molecular cause is a point mutation in mitochondrial DNA, the m.8993T>G change in MT-ATP6, which disrupts a subunit of ATP synthase (complex V) and therefore cripples oxidative phosphorylation. Since the gene sits in the mitochondrial genome, the disease is transmitted maternally, and a heavier burden of the identical mutation tips the phenotype into maternally inherited Leigh syndrome, both facts confirming its mitochondrial nature.
None of the storage-disease categories fit: glycogen storage diseases, lysosomal storage diseases and lipid storage diseases each stem from specific enzyme deficiencies in carbohydrate, lysosomal or lipid metabolism rather than from a failure of the respiratory chain.
Hence NARP belongs to the mitochondrial functional disorders.
\[\boxed{\text{Mitochondrial function disorder}}\]
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