### SNORD109B Gene Overview

**Gene Symbol:** SNORD109B  
**Description:** SNORD109B is classified as a C/D box-type small nucleolar RNA (snoRNA) that plays a role in the modification of other RNA molecules, predominantly rRNA, through methylation. It is primarily expressed in the brain, and interestingly, its expression is not detectable in the brains of individuals with Prader-Willi syndrome. This suggests a potential involvement of SNORD109B in neurological functions or disorders.

### 1. Associated Genes
While specific information regarding genes directly associated with SNORD109B is limited and not frequently reported, the following are related or potentially co-regulated genes based on known snoRNA functions and interactions within the nucleolus:
- **SNORD109A:** A closely related snoRNA may have overlapping functions and expression patterns.
- **Ribosomal protein genes (e.g., RPL11, RPL23):** Since snoRNAs typically assist in rRNA processing, genes encoding ribosomal proteins may be functionally linked.
- **Other C/D box snoRNA genes.**

### 2. Aging and Age-Related Diseases
Current literature specifically linking SNORD109B to aging or age-related diseases is sparse. However, alterations in the expression of various snoRNAs, including C/D box snoRNAs, have been implicated in:
- **Neurodegenerative diseases:** Changes in snoRNA expression in relation to diseases like Alzheimer's could suggest a role in neurodegeneration, though specific studies on SNORD109B are lacking.
- **Developmental disorders:** Its absence in Prader-Willi syndrome indicates potential implications in genetic regulation related to developmental milestones and neurodevelopmental disorders.

### 3. Drug Interactions
Currently, there are no specific drugs or drug classes identified that interact directly with SNORD109B documented in major databases. Given that snoRNAs often act within cellular machinery rather than as direct drug targets, their specific interactions with pharmacological agents may not be well-characterized. Further research may identify indirect associations, but as of now, no direct interactions have been established.

### 4. Pathways and Biological Processes
SNORD109B is involved in several biological processes and molecular pathways:
- **Ribosome biogenesis:** As a snoRNA, its primary function impacts the processing and modification of rRNA, which is essential in the formation of ribosomes.
- **Nuclear processes:** It plays a role in nucleolar function, affecting RNA metabolism and surveillance within the nucleus.
- **Methylation:** SNORD109B is part of methylation processes, particularly methylating rRNA targets which are crucial for ribosomal function and protein synthesis.
- **Neuronal function:** Given its predominant expression in the brain, SNORD109B may be involved in specific neurological processes, potentially influencing neuronal development and function.
  
### Summary
SNORD109B is a C/D box-type small nucleolar RNA primarily expressed in the brain, with potential links to neurological disorders, evidenced by its absence in Prader-Willi syndrome. Further research is warranted to explore its full functional spectrum, especially concerning its role in aging and age-related diseases. However, precise associations, especially concerning drug interaction and specific pathways, are limited and require additional investigation.