**Core Concept**
Snurps (small nuclear RNAs, U6-type) are a class of small nuclear RNAs involved in the splicing process of pre-mRNA. They function as part of the spliceosome, a complex molecular machine responsible for removing introns and joining exons during RNA processing.

**Why the Correct Answer is Right**
A defect in snurps leads to a specific type of genetic disorder characterized by the inability to properly splice pre-mRNA. This results in the accumulation of aberrant mRNA and subsequent production of truncated proteins, which can be toxic to cells. The splicing defect is due to the failure of the snurps to properly interact with the pre-mRNA, leading to aberrant splicing patterns.

**Why Each Wrong Option is Incorrect**
**Option A:** Defects in snurps have not been associated with mitochondrial function or disorders.
**Option B:** While defects in snurps can lead to genetic disorders, they are not typically associated with chromosomal abnormalities or aneuploidy.
**Option C:** Snurps are not directly involved in the regulation of gene expression through epigenetic modifications.

**Clinical Pearl / High-Yield Fact**
Defects in snurps can lead to a range of genetic disorders, including spinal muscular atrophy (SMA), a devastating neuromuscular disease characterized by progressive muscle weakness and paralysis.

**Correct Answer: D. Spinal Muscular Atrophy (SMA)**