*Review* **Molecular Functionality of Cytochrome P450 4 (CYP4) Genetic Polymorphisms and Their Clinical Implications**

**Yazun Bashir Jarrar <sup>1</sup> and Su-Jun Lee 2,\***


Received: 18 July 2019; Accepted: 28 August 2019; Published: 31 August 2019

**Abstract:** Enzymes in the cytochrome P450 4 (CYP4) family are involved in the metabolism of fatty acids, xenobiotics, therapeutic drugs, and signaling molecules, including eicosanoids, leukotrienes, and prostanoids. As CYP4 enzymes play a role in the maintenance of fatty acids and fatty-acid-derived bioactive molecules within a normal range, they have been implicated in various biological functions, including inflammation, skin barrier, eye function, cardiovascular health, and cancer. Numerous studies have indicated that genetic variants of *CYP4* genes cause inter-individual variations in metabolism and disease susceptibility. Genetic variants of *CYP4A11*, *4F2* genes are associated with cardiovascular diseases. Mutations of *CYP4B1*, *CYP4Z1*, and other *CYP4* genes that generate 20-HETE are a potential risk for cancer. *CYP4V2* gene variants are associated with ocular disease, while those of *CYP4F22* are linked to skin disease and *CYP4F3B* is associated with the inflammatory response. The present study comprehensively collected research to provide an updated view of the molecular functionality of *CYP4* genes and their associations with human diseases. Functional analysis of *CYP4* genes with clinical implications is necessary to understand inter-individual variations in disease susceptibility and for the development of alternative treatment strategies.

**Keywords:** *CYP4* genes; genetic polymorphisms; 20-HETE; fatty acid; arachidonic acid; SNPs; molecular functionality; metabolism; lamellar ichthyosis; Bietti's crystalline dystrophy
