### PHEX-AS1 Gene Overview

**Gene Symbol**: PHEX-AS1  
**Gene Type**: Long non-coding RNA (lncRNA)  
**Location**: Chromosome X  
**Function**: PHEX-AS1 is an antisense RNA for the PHEX gene, which is known to play a role in phosphate metabolism and is associated with X-linked hypophosphatemia. As a lncRNA, PHEX-AS1 may be involved in the regulation of gene expression and has been implicated in various biological processes.

### 1. Associated Genes

While specific interactions may not always be thoroughly documented in databases, genes that are often mentioned in relation to PHEX include:

- **PHEX**: The most direct association, as PHEX-AS1 is an antisense RNA to this gene.
- **FGF23 (Fibroblast Growth Factor 23)**: This gene is involved in phosphate homeostasis and is linked to conditions regulated by PHEX.
- **SLC34A1 and SLC34A3**: These sodium-dependent phosphate transporters have been investigated in connection with phosphate metabolism and may have indirect connections with PHEX pathways.
- **KIDINS220**: Recent studies suggest associations in pathological contexts like cancer where PHEX-AS1 may exert regulatory functions.

### 2. Aging and Age-Related Diseases

Research involving PHEX-AS1 has shown:

- **Aging**: Some studies have found that disturbances in phosphate metabolism, which may involve PHEX-AS1, have associations with aging processes. Phosphate levels and homeostasis can affect bone health, kidney function, and cardiovascular diseases prevalent in older populations.
  
- **Age-Related Diseases**: Dysregulation of phosphate metabolism, as can occur when PHEX-AS1 or PHEX are dysfunctional, is linked to osteomalacia, rickets, and other bone-related diseases. Additionally, since phosphate homeostasis is important for cardiovascular health, abnormalities may contribute to age-related cardiovascular diseases.

### 3. Drug Interactions

Data directly linking drug interactions with PHEX-AS1 is not widely documented, but:

- **Phosphate binders**: Drugs such as sevelamer and lanthanum carbonate, which are used to manage phosphate levels, may indirectly relate to the pathways involving PHEX and thus may affect gene expression levels of lncRNAs like PHEX-AS1.
  
- **Calcitriol**: As vitamin D plays a role in calcium and phosphate metabolism, drugs or supplements affecting vitamin D levels might also indirectly influence the expression or function of PHEX-AS1 through its connections with PHEX and phosphate metabolism.

### 4. Pathways and Biological Processes

PHEX-AS1 potentially participates in several pathways and biological processes, including:

- **Phosphate Metabolism**: Given its relationship with PHEX, PHEX-AS1 is likely involved in the modulation of phosphate levels.
- **Bone Remodeling**: Since PHEX influences FGF23, a crucial factor in bone metabolism, PHEX-AS1 might play a part in signals related to osteogenesis or osteoclastogenesis.
- **Cellular Signaling**: As a lncRNA, PHEX-AS1 might be involved in various signaling pathways via regulation of transcription or interactions with proteins involved in signaling cascades.
- **Pathways Associated with Mineral Homeostasis**: It might also be implicated in hormonal feedback loops related to parathyroid hormone and vitamin D pathways.
  
### Summary

PHEX-AS1 is a long non-coding RNA linked to gene regulation and metabolic pathways associated with phosphate homeostasis and potential implications in aging and age-related diseases. Further studies are needed to elucidate its exact roles and interactions in health and disease contexts. This gene's implications may extend into therapeutic areas concerned with mineral metabolism and associated pathologies.