Clinical and molecular genetic findings of hereditary Parkinson's patients from Turkey.


Emekli I. , Tepgeç F., Samancı B. , Toksoy G. , Hasanoğulları Kına G., Tüfekçioğlu Z., ...More

Parkinsonism & related disorders, vol.93, pp.35-39, 2021 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 93
  • Publication Date: 2021
  • Doi Number: 10.1016/j.parkreldis.2021.10.024
  • Journal Name: Parkinsonism & related disorders
  • Journal Indexes: Science Citation Index Expanded, Scopus, Academic Search Premier, CINAHL, EMBASE, MEDLINE, Psycinfo
  • Page Numbers: pp.35-39
  • Keywords: Molecular genetics analysis, Early-onset PD, Consanguinity, Variant, ONSET PARKINSONISM, MUTATIONS, DISEASE, PHENOTYPES

Abstract

Introduction

The majority of Parkinson's disease (PD) ensue late-onset with a complex spectrum of environmental and genetic risk factors. Awareness of genetic causes in patients with PD is essential for genetic counseling and future genotype-oriented therapeutic developments.

Methods

Large pathogenic changes in eight PD-related genes and small pathogenic sequence variants in 22 PD-related genes were investigated simultaneously in 82 PD patients from 79 families where clinical evaluations were performed. The phenotypic characteristics of the patients with molecular changes were examined for genotype-phenotype relations.

Results

Pathogenic variants in SNCAPRKNDJ-1FBXO7, and GBA genes were determined in 25 patients from 24 families (24/79, 30%). Associated variants were found in PRKN in 14, SNCA in three, FBXO7 in two, and DJ-1 in one patient. A novel homozygous deletion (c.491delT, p.(V164Dfs*13) (SCV001733595)) leading to protein truncation in the PRKN gene was identified in two patients from the same family. Furthermore, heterozygous GBA gene variants were detected in five patients from different families.

Conclusion

It has been shown that the most common cause of genetically transmitted PD is the PRKN gene, while LRRK2 does not play an essential role in this selected population. It has been suggested that even if the autosomal recessive inheritance is expected, genes with autosomal dominant effects such as SNCA should not be overlooked and suggested for investigation. Our study is also the first for evaluating the pathogenic GBA variants’ frequency in PD patients from Turkey.