The GCNT1P3 gene, also known as Generalized Carbohydrate N-acetylglucosaminyltransferase 1 pseudogene 3, is a pseudogene related to the GCNT1 gene, which encodes a glycosyltransferase involved in glycan biosynthesis and modification. Below is a more detailed overview of GCNT1P3 as requested.

1. **Associated Genes**:
   - **GCNT1**: The most closely related gene, known for its role in producing the enzyme responsible for the addition of N-acetylglucosamine to O-glycans.
   - **Other genes in glycan biosynthesis**: While GCNT1P3 itself is a pseudogene and does not translate into a protein, it is associated with genes involved in glycan metabolism, such as those in the glycosyltransferase family.

2. **Aging and Age-related Diseases**:
   - Currently, there is limited direct information regarding GCNT1P3's role in aging or age-related diseases in the literature. However, its closely related gene, GCNT1, may play indirect roles in processes such as inflammation, tumor progression, and neurodegenerative diseases due to its involvement in glycosylation, which is essential for cellular communication and immune response.
   - Variations in glycosylation patterns have been linked to several age-related diseases, which suggests that research concerning GCNT1 and its functional networks could provide insights into potential aging mechanisms related to GCNT1P3.

3. **Drug Interactions**:
   - As a pseudogene, GCNT1P3 does not encode a functional protein and therefore does not have direct drug interactions or be the target of specific drug classes. However, research on its functional relatives, like GCNT1, could yield information on glycosylation inhibitors or modulators that affect glycosyltransferase activities.

4. **Pathways and Biological Processes**:
   - **Glycosylation**: Primarily associated with the process of glycosylation, which involves the addition of carbohydrates to proteins and lipids. This process is critical for proper protein folding, stability, and cell signaling.
   - **Cell adhesion and immune response**: Given its relationship with GCNT1, GCNT1P3 may indirectly influence pathways involved in cell adhesion and immune response modulation.
   - **Development and cellular processes**: Closely linked with various biological pathways that pertain to cellular development and function, though direct contributions from GCNT1P3 may remain speculative due to its pseudogene status.

In summary, while GCNT1P3 is primarily understood as a pseudogene with no protein-coding capacity, it bears significance through its relationship to glycosylation processes that could influence aging and related biological pathways. Future research may clarify its indirect roles, particularly in conjunction with its associated gene GCNT1 and broader cellular processes.