Ali Khodadadian - Department of Human Genetics, Faculty of Medicine, University of Shahid Sadoughi, Yazd, Iran
Ali Mota - Department of Clinical biochemistry and laboratory medicine, Faculty of Medicine, Tabriz University of medical sciences, Tabriz, Iran
Mohsen Hemmati-Dinarvand - Department of Clinical biochemistry and laboratory medicine, Faculty of Medicine, Tabriz University of medical sciences, Tabriz, Iran
Emad Babakhanzade - Department of Human Genetics, Faculty of Medicine, University of Shahid Sadoughi, Yazd, Iran

Parkinson disease (PD) after Alzheimer is the second most common disease associated with neurodegenerative disorders. Itaffects 2 to 3 percent of the individuals over 65 years of age. Destruction of neurons in the substantia nigra, which causesstriatal dopamine deficiency, and intracellular inclusions containing aggregates of α‑synuclein are the neuropathologicaldominant symptoms of PD. The premature state of PD is familial, which is known as early onset PD (EOPD) and a smallportion of the cases have been involved, which disease occurs at the age of less than 60 years. Although individuals who aresuffering from the EOPD may have genetic changes, but the molecular mechanisms that can differentiate between EOPD andlate onset PD (LOPD) has remained unclear. Recent studies have revealed different gene profiles between healthy controls andpatients with sporadic and familial PD. Also related to these genes, some studies have been done on microRNAs, which led tothe identification of certain types of them. These microRNAs are associated with PD through various pathways, includingcontrol of neuron development, mitochondrial dysfunction, and oxidative stress. Because of complexity of treatment processand control of PD progression, these microRNAs can be used as a biomarker for early diagnosis of PD, especially EOPD. PD isusually diagnosed in late-stages (i.e., When the amount of dopamine significantly reduced). Therefore, it seems necessary toidentify biomarkers for early-stage diagnosis. This article tries to review some of the most important recognized biomarkers,such as the microRNAs related to PD.

Parkinson Disease, Neurodegenerative, MicroRNA, Biomarkers, Dopamine Deficiency