The PDXDC1 gene (pyridoxal-dependent decarboxylase 1) is known to encode a protein that is believed to have roles in metabolic processes, particularly those involving carboxylic acids. Here is a detailed overview of the gene based on your request:

### General Information:
- **Gene Symbol**: PDXDC1
- **Location**: Golgi apparatus
- **Cofactor Binding**: The protein encoded by PDXDC1 is predicted to have a cofactor binding site, likely for pyridoxal phosphate, which can be important for catalytic activity.

### 1. Associated Genes:
While specific lists of direct associated genes for PDXDC1 are not widely reported, it may interact with or be co-regulated with genes involved in metabolic processes or those within similar pathways, such as:
- **PDX1**: Related to pancreatic development, which could have indirect associations.
- **ACLY**: Involved in acetic acid metabolism.
- **ALAD**: Involved in heme biosynthesis, which may overlap in metabolic pathways with PDXDC1.

Given the gene's predicted role in carboxylic acid metabolism, other genes within the metabolic pathways of amino acids or fatty acids could also be considered indirectly associated.

### 2. Aging and Age-Related Diseases:
Currently, specific literature linking PDXDC1 directly to aging or age-related diseases is limited. However, genes involved in metabolic processes can have downstream effects on:
- **Cellular metabolism**: Changes in metabolism are known to influence aging.
- **Neurodegeneration**: Gene expression changes in metabolism related to amino acids may influence age-related diseases like Alzheimer’s or Parkinson's.

Future studies might explore its role or expression in the context of age-related diseases more thoroughly.

### 3. Drug Interactions:
As of the latest data available until October 2023, there are no specific drugs or drug classes widely known to directly interact with PDXDC1. However, medications that affect metabolic pathways in general or compound classes targeting metabolic processes might indirectly influence its activity or expression. More investigational drugs aimed at metabolic regulation could be explored.

### 4. Pathways and Biological Processes:
PDXDC1 is predicted to be involved in several biological processes and pathways:
- **Carboxylic acid metabolic processes**: As indicated in the summaries, the gene plays a crucial role in the metabolism of these compounds.
- **Cellular metabolism**: It could be indirectly involved in broader metabolic pathways affecting amino acids or energy metabolism.
- **Binding Activities**: The cadherin binding activity may suggest a role in cellular adhesion, which is critical for maintaining tissue structure, cellular communication, and signaling, although this aspect might require further experimental validation.

### Summary
To summarize, PDXDC1 is implicated in metabolic processes related to carboxylic acids, has potential interactions with other metabolic genes, and while currently lacking strong direct ties to aging or drug interactions, it remains a candidate for further research in the context of metabolism and its effects on aging and age-related diseases. As more research is conducted, especially involving genetics and metabolic pathways, the understanding of its functions may evolve significantly.