Exon deletions of parkin gene in patients with Parkinson disease

Mutations in PRKN and SNCA Genes Important for the Progress of Parkinson's Disease

Although Parkinson’s disease (PD) was first described almost 200 years ago, it remains an incurable disease with a cause that is not fully understood. Nowadays it is known that disturbances in the structure of pathological proteins in PD can be caused by more than environmental and genetic factors. Despite numerous debates and controversies in the literature about the role of mutations in the SNCA and PRKN genes in the pathogenesis of PD, it is evident that these genes play a key role in maintaining dopamine (DA) neuronal homeostasis and that the dysfunction of this homeostasis is relevant to both familial (FPD) and sporadic (SPD) PD with different onset. In recent years, the importance of alphasynuclein (ASN) in the process of neurodegeneration and neuroprotective function of the Parkin is becoming better understood. Moreover, there have been an increasing number of recent reports indicating the importance of the interaction between these proteins and their encoding genes. Among others interactions, it is suggested that even heterozygous substitution in the PRKN gene in the presence of the variants +2/+2 or +2/+3 of NACP-Rep1 in the SNCA promoter, may increase the risk of PD manifestation, which is probably due to ineffective elimination of over-expressed ASN by the mutated Parkin protein. Finally, it seems that genetic testing may be an important part of diagnostics in patients with PD and may improve the prognostic process in the course of PD. However, only full knowledge of the mechanism of the interaction between the genes associated with the pathogenesis of PD is likely to help explain the currently unknown pathways of selective damage to dopaminergic neurons in the course of PD.

PARK2 gene mutations in early onset Parkinson's disease patients of South India

With the etiology being unclear till date, a combination of age, genetic and environmental factors are known to play a significant role in the pathogenesis of Parkinson's disease. Mutations in PARK2 gene have been implicated to cause autosomal recessive early onset PD. We analyzed the 12 coding exons of PARK2 gene in 16 early onset PD patients of South Indian ethnicity. PARK2 mutations were present in 68% of the early onset cases. We report the presence of four PARK2 sequence variants c.1239G>C, c.171+25T>C, c.202A>G, c.601G>A, and a novel insertion mutation, c.798_799insA in the exon 7 of PARK2 gene. These results suggest that mutations in PARK2 gene may be a common cause of PD among South Indian early onset patients.