### SEM1 Gene Overview

**Gene Symbol**: SEM1  
**Chromosomal Location**: Located at the split hand/split foot malformation locus SHFM1 on chromosome 7.  

#### Role and Function:
The SEM1 gene encodes a protein that has been implicated in several cellular processes, including the completion of the cell cycle. Its interaction with BRCA2 suggests a potential role in DNA repair mechanisms and maintaining genomic stability. The gene has been considered a candidate for the autosomal dominant form of split hand/split foot malformation type 1, a congenital limb disorder characterized by the partial or complete absence of the central part of the hand or foot.

### 1. Associated Genes:
- **BRCA2**: As noted, SEM1 interacts directly with BRCA2, a gene essential for the repair of DNA double-strand breaks and maintenance of genomic integrity.
- **FBXW7**: While not directly mentioned in the summaries, SEM1 may also play a role in the degradation of certain proteins involved in the cell cycle, such as those regulated by the F-box/WD repeat-containing protein 7 (FBXW7) pathway.
- **Other genes in the SHFM1 locus**: Other genes associated with the split hand/split foot malformation phenotype may indirectly relate to SEM1.

### 2. Aging and Age-Related Diseases:
- **Genomic Stability**: Given SEM1's interaction with BRCA2, it may indirectly relate to age-related diseases associated with genomic instability, such as cancer. The role of BRCA2 in breast and ovarian cancers points to the possibility that variations or dysfunctions associated with SEM1 may manifest more prominently in older populations, particularly in the context of cancer predisposition.
- **Cell Cycle Regulation**: Disruptions in cell cycle regulation can contribute to aging and age-related cellular dysfunction, impacting tissue repair and regeneration.

### 3. Drug Interactions:
Currently, there is limited specific information regarding drugs directly targeting SEM1 or its protein product. However, given its interaction with BRCA2, drugs that are part of targeted cancer therapies, such as:
- **PARP inhibitors (e.g., Olaparib, Niraparib)**: These are used in BRCA-mutated tumors and might indirectly affect frames related to SEM1 due to its involvement with BRCA2.
- **Chemotherapeutic agents**: Agents that induce DNA damage could alter the functioning of pathways that involve SEM1 and BRCA2, although they do not target SEM1 directly.

### 4. Pathways and Biological Processes:
SEM1 is involved in several biological processes:
- **Cell Cycle Regulation**: Its role in the completion of the cell cycle suggests it is involved in checkpoints and progression through the cycle.
- **DNA Repair**: Interaction with BRCA2 places SEM1 within pathways critical for DNA repair, particularly in rectifying double-strand breaks.
- **Limb Development**: Mutations or alterations in SEM1 are associated with the embryological development processes governing limb patterning, particularly for the split hand/foot malformation.
- **Proteasome-mediated Degradation**: SEM1 might be implicated in pathways related to protein degradation, especially concerning cell cycle regulators.

### Conclusion
The SEM1 gene is crucial for various cellular functions and developmental processes, with potential implications in health and disease, particularly regarding limb malformations and genomic stability. Further study and exploration into its roles, especially concerning interactions with other genes and potential drug effects, are essential for clarifying its functions in both normal physiology and in disease states.