Summary:
Background – Aim of the study: In the recent years, there has been great
progress in the research on Parkinson’s disease (PD) and a vast amount of data
supports its genetic etiology. About 5-10% of the patients with PD have been
shown to have a monogenetic form of PD, and carry a single genetic defect that
causes the disease. The aim of the present study was to investigate the genetic
basis of PD in the islands of Cyclades.
Methods: Ιn this regard we performed two parallel studies: a) a Familial
Aggregation study of PD in the island of Syros, and b) a Genetic study,
searching for known mutations or other genetic defects in genes known to be
related with PD in patients with PD from Cyclades. Specifically, we focused our
research on the genes SNCA, LRRK2, VPS35, GBA, Parkin, DJ-1 and PINK1.
Results: From a total of 71 patients with PD from Syros who participated in the
Familial Aggregation study, 28 (25.3%) had a first degree relative with PD in
comparison with 10 out of 175 controls (5.7%) (OR= 5.6; 95% CI= 2.4, 12.9).
Genetic analysis revealed a heterozygous dosage mutation (ex2-3dup) in Parkin
gene, a common polymorphism (M2397T, MAF= 56.1%) in LRKK2 gene with a
protective influence (OR= 0.34, 95% CI= 0.15, 0.78) and 6 patients and 1
control with a mutation in GBA gene (4 patients carried the L444P mutation and
2 patients and the control carried the N370S mutation)
Conclusions: Despite the results from the Familial Aggregation study supporting
a strong genetic component in the etiology of PD in Syros (patients with PD
were 5 times more likely to have a first degree relative with PD in relation to
controls), the genetic defects in known genes that were studied were proved not
to be related with PD in Cyclades. Therefore, it is possible that other still
unknown genetic factors are responsible for the genetic basis of PD in
Cyclades.
Keywords:
Parkinson's disease, Genetic analysis, Genes, Familial aggregation, Cyclades
