REP1 associated with a reduced risk for PD and

REP1 a polymorphic microsatellite repeat site located on the
SNCA promoter site. Many studies reported that an expanded length of the allele
is associated with an increased risk of PD. Rep1 allele is hypothesized to have
an effect on the transcriptional regulatory element that modulates the
expression of ?-synuclein (Maraganore et al. 2006), (Touchman
et al. 2001), (Chiba et al 2001). Short alleles genotype was associated with a
reduced risk for PD and low mRNA and protein levels, while long alleles were
associated with an increased risk for PD and high levels of mRNA and protein. In
fact, there was a two-fold difference in PD susceptibility between individuals
who homozygous for short alleles versus homozygous for long alleles
(Cronin et al. 2009), (Linnertz et al. 2009), (Campelo et al. 2017). Polymorphism of the 5? region (rs2583988) a single
nucleotide polymorphisms located at the 5′ region, this polymorphism is in a
linkage disequilibrium with other polymorphisms. But no significant results or
correlation had been shown with this SNP in regard to SNCA mRNA levels (Linnertz
et al. 2009), (Campelo et al. 2017). This SNP
is in a linkage disequilibrium with rs181489 (Ross et al.2007). In a study done by Elbaz et al. they found that there
is an interaction between rs2583988 and rs356219,
this interaction suggests that 5’end SNPs has an effect among carriers of 3’SNPs
(rs356219 alleles). (Elbaz et al.2011), (Campelo
et al. 2017).