### GCDH Gene Summary

**Gene Symbol:** GCDH  
**Location:** Chromosome 19  
**Description:** The GCDH (glutaryl-CoA dehydrogenase) gene encodes a mitochondrial enzyme that plays a crucial role in the metabolism of certain amino acids, notably L-lysine, L-hydroxylysine, and L-tryptophan. The enzyme catalyzes the oxidative decarboxylation of glutaryl-CoA to crotonyl-CoA and CO₂, using electron transfer flavoprotein as an electron acceptor. It is composed of homotetrameric subunits, functioning predominantly in the mitochondrial matrix.

**Diseases Associated:** Mutations in GCDH are linked to glutaric aciduria type 1 (also referred to as glutaric acidemia type I), a metabolic disorder characterized by the accumulation of glutaric acid and related compounds due to impaired metabolism.

### Additional Information

1. **Genes Associated with GCDH:**
   - **ETFA, ETFB, and ETFDH:** These genes are associated with mitochondrial electron transfer and energy metabolism and could be relevant due to their involvement in the electron transfer pathway that the GCDH enzyme utilizes.
   - **GLUD1:** The glutamate dehydrogenase gene could interact with pathways involving amino acid metabolism.
   - **SLC7A7 and SLC1A5:** Known to be involved in transport pathways of amino acids, indirectly related to the metabolic pathways involving GCDH.

2. **Aging and Age-Related Diseases:**
   - There is not a direct link established between GCDH and aging or age-related diseases in the current literature. However, metabolic dysfunctions can lead to various age-related conditions. The accumulation of metabolites due to GCDH deficiencies might have implications on neurodegenerative diseases and mitochondrial dysfunction, which are common in aging populations.

3. **Drugs or Drug Classes Interacting with GCDH:**
   - Currently, there are no specific drugs that directly interact with the GCDH protein. However, supportive treatments for glutaric aciduria type 1 often include dietary management such as lysine restriction and supplementation with certain cofactors (e.g., carnitine), which can indirectly relate to metabolic pathways impacted by GCDH.

4. **Pathways and Biological Processes:**
   - **Lysine catabolism:** GCDH is primarily involved in lysine degradation pathways.
   - **Amino acid metabolism:** The enzyme plays a role in the metabolism of several amino acids beyond lysine, including L-hydroxylysine and L-tryptophan.
   - **Mitochondrial fatty acid metabolism:** Due to the enzyme's function in the mitochondrial matrix, it relates to pathways involving the metabolism of fatty acids and their derivatives.
   - **Electron transport:** Involvement in mitochondrial electron transfer pathways is crucial as it acts on flavoproteins.

### Conclusion
The GCDH gene is vital in the metabolism of certain amino acids, and its dysfunction can lead to metabolic disorders with significant implications for overall health. Further research may uncover more about its role in aging processes and potential interactions with pharmacological agents targeting metabolic pathways.