Publications by authors named "Athina Simitsi"
Article Synopsis
- The study explores how copy number variations (CNVs) affect the development of Parkinson's disease (PD), aiming to identify new genetic mechanisms linked to sporadic cases of the disease.
- Utilizing data from over 11,000 PD patients and nearly 9,000 controls, the researchers discovered 14 significant CNV loci associated with PD, including various gene duplications and deletions.
- The research highlights a higher prevalence of CNVs in specific PD-related genes among patients and suggests that certain CNVs, especially those involving the gene, may lead to earlier onset of the disease in early-onset PD cases.
Article Synopsis
- The study investigates the relationship between body mass index (BMI) and Parkinson's disease (PD) using a method called Mendelian randomization to determine if higher genetically predicted BMI is linked to a lower incidence of PD.
- Researchers analyzed genetic data from large groups of individuals, including over 800,000 for BMI and nearly 29,000 for PD, focusing on factors like age, disease duration, and gender to examine the associations.
- Results indicated an inverse relationship between genetically predicted BMI and PD, particularly among younger participants and women, suggesting that lower BMI may be associated with a higher risk of developing Parkinson's disease.
Article Synopsis
- - Impulse Control Disorders (ICDs) like pathological gambling and compulsive eating are significant non-motor symptoms in Parkinson's Disease, with a prevalence around 10% to much higher based on different studies.
- - A two-part study was conducted with 892 Greek PD patients to assess the incidence of ICDs and explore psychological factors such as personality traits and quality of life.
- - Preliminary results show that 12.4% of patients had ICDs and highlight the role of heightened activity and coping mechanisms in developing these disorders, emphasizing compulsivity over impulsivity.
Introduction: There has been a bias in the existing literature on Parkinson's disease (PD) genetics as most studies involved patients of European ancestry, mostly in Europe and North America. Our target was to review published research data on the genetic profile of PD patients of non-European or mixed ancestry.
Methods: We reviewed articles published during the 2000-2023 period, focusing on the genetic status of PD patients of non-European origin (Indian, East and Central Asian, Latin American, sub-Saharan African and Pacific islands).
Background: Some reports suggest that psychotic features may occur in the early stages of Parkinson's disease (PD), but sensitive tools have not been utilized.
Objective: The aim was to evaluate the presence of psychotic symptoms using detailed scales and to assess the association with clinical characteristics.
Methods: Healthy controls and patients within three years of PD onset were recruited.
Article Synopsis
- The study looked at how patients with early Parkinson's disease (PD) tend to jump to conclusions and how that relates to other symptoms they might have.
- It found that more PD patients (32%) showed this jumping to conclusions compared to healthy individuals (9%).
- The researchers think that impulsive behaviors might be linked to the way these patients think, but they need to do more research to understand how everything connects.
Article Synopsis
- Epidemiological studies have shown mixed results regarding the link between Parkinson's disease (PD) and various cancers, primarily due to methodological challenges.
- This research aimed to explore the genetic correlation between PD and different cancers using data from large genome-wide association studies (GWASs) involving thousands of participants, particularly those of European ancestry.
- Findings revealed a positive genetic correlation between PD and melanoma as well as prostate cancer, while showing inverse associations between PD and ovarian cancer, indicating complex genetic interactions between these diseases.
Article Synopsis
- - This study investigates the genetic factors influencing the age at onset (AAO) of Parkinson's disease (PD), aiming to address the inconsistencies in previous research and validate findings through a meta-analysis of diverse populations.
- - The meta-analysis combined data from the COURAGE-PD Consortium, which included over 8,500 patients primarily of European origin, and the International Parkinson Disease Genomics Consortium, reaching a total of nearly 26,000 participants.
- - The research confirmed a known genetic variant associated with PD AAO and discovered two genome-wide significant signals on chromosome 4, contributing new insights into the genetic basis of the disease's onset.
Article Synopsis
- Two contrasting studies previously examined the link between the HLA-DRB1 gene and smoking concerning Parkinson's disease (PD), leading to varying conclusions.
- This research aimed to replicate those findings by analyzing genetic data from over 12,000 PD cases and nearly 9,500 controls, focusing on specific genetic variants related to smoking.
- The results indicated that a specific variant in the HLA-DRB1 gene (valine at position 11) was significantly associated with PD, revealing an inverse relationship between smoking initiation and PD only in individuals lacking this variant, which invites further investigation into the underlying mechanisms.
Despite several advances in the field, pharmacodynamic outcome measures reflective of LRRK2 kinase activity in clinical biofluids remain urgently needed. A variety of targets and approaches have been utilized including assessments of LRRK2 itself (levels, phosphorylation), or its substrates (e.g.
View Article and Find Full Text PDFWe assessed non motor characteristics of 12 asymptomatic p.A53T mutation carriers (A53T-AC) compared with 36 healthy controls (HC) enrolled in the Parkinson's Progression Markers Initiative (PPMI) study. Olfaction score was lower and anxiety was marginally more prevalent in A53T- AC.
View Article and Find Full Text PDFArticle Synopsis
- Previous studies suggested that dairy intake may increase the risk of Parkinson's disease (PD), especially in men, but the nature of this relationship was unclear.
- This research used genetic data to investigate the link between dairy consumption and PD through a method called Mendelian randomization, involving nearly 10,000 patients and 8,000 controls.
- The results indicated that genetically predicted higher dairy intake is associated with an increased risk of PD, particularly in men, providing evidence for a possible causal relationship.
Article Synopsis
- The study investigates how lifestyle factors like smoking, alcohol, and coffee consumption relate to Parkinson's disease (PD), using a genetic approach to avoid potential biases in causation.* -
- Findings indicate that smoking is significantly associated with a lower risk of developing PD, while no such associations were found for alcohol or coffee consumption, though there is a suggestion that genetic vulnerability to PD might increase alcohol drinking.* -
- The research concludes that the protective effect of smoking on PD is likely genuine and not influenced by reverse causation or other biases; however, the data on alcohol and coffee remains inconclusive due to limited power.*
Apathy: An underestimated feature in GBA and LRRK2 non-manifesting mutation carriers.
Parkinsonism Relat Disord
October 2021
Introduction: Higher prevalence of motor and non-motor features has been observed in non-manifesting mutation carriers of Parkinson's Disease (PD) compared to Healthy Controls (HC). The aim was to detect the differences between GBA and LRRK2 mutation carriers without PD and HC on neuropsychiatric symptoms.
Methods: This is a cross-sectional retrospective study of non-manifesting GBA and LRRK2 mutation carriers and HC enrolled into Parkinson's Progression Markers Initiative (PPMI).
Background: The SNCA gene encoding α-synuclein (αSyn) is the first gene identified to cause autosomal-dominant Parkinson's disease (PD).
Objective: We report the identification of a novel heterozygous A30G mutation of the SNCA gene in familial PD and describe clinical features of affected patients, genetic findings, and functional consequences.
Methods: Whole exome sequencing was performed in the discovery family proband.
Study Objectives: Τo assess whether REM Sleep Behavior Disorder (RBD) and other sleep abnormalities occur in carriers of the p.A53T alpha-synuclein gene (SNCA) mutation, using both subjective and objective measures.
Methods: We have assessed 15 p.
Objective: There is a pressing need to identify and validate, minimally invasive, molecular biomarkers that will complement current practices and increase the diagnostic accuracy in Parkinson's disease (PD). Brain-enriched miRNAs regulate all aspects of neuron development and function; importantly, they are secreted by neurons in amounts that can be readily detected in the plasma. Τhe aim of the present study was to validate a set of previously identified brain-enriched miRNAs with diagnostic potential for idiopathic PD and recognize the molecular pathways affected by these deregulated miRNAs.
View Article and Find Full Text PDFBackground: Because of the highly penetrant gene mutation and clinical features consistent with idiopathic Parkinson's disease, carriers of the autosomal dominant Ala53Thr (A53T; 209G→A) point mutation in the α-synuclein (SNCA) gene are an ideal population to study the premotor phase and evolution of Parkinson's pathology. Given the known neurochemical changes in the serotonergic system and their association with symptoms of Parkinson's disease, we hypothesised that carriers of the A53T SNCA mutation might show abnormalities in the serotonergic neurotransmitter system before the diagnosis of Parkinson's disease, and that this pathology might be associated with measures of Parkinson's burden.
Methods: In this cross-sectional study, we recruited carriers of the A53T SNCA mutation from specialist Movement Disorders clinics in Athens, Greece, and Salerno, Italy, and a cohort of healthy controls with no personal or family history of neurological or psychiatric disorders from London, UK (recruited via public advertisement) who were age matched to the A53T SNCA carriers.
Background: The p.A53T point mutation in the α-synuclein gene (SNCA) is a rare but highly relevant cause of autosomal dominant Parkinson's disease (PD).
Objectives: The objective of this study was to assess striatal dopaminergic denervation in a cohort of symptomatic carriers of the p.
We compared phenotypic characteristics in 35 Greek patients with Parkinson's disease (PD), carriers of GBA1 mutations (GBA-PD), with 35 Genetically Unidentified PD patients (GU-PD). We found a previously reported higher prevalence of cognitive impairment and a little appreciated more frequent bilateral onset of the disease in GBA-PD vs GU-PD. As far as the exposure to environmental factors, linked to PD, is concerned, our study hints to the possibility that pesticide exposure may be more common in GBA-PD patients, and possibly act synergistically with the mutation carrier status to trigger the disease.
View Article and Find Full Text PDFObjective: To evaluate nonmotor symptoms in early /p.A53T Parkinson disease (PD) (A53T PD) compared to typical PD (tPD).
Methods: The presence of hyposmia, neuropsychiatric, dysautonomic, and sleep disturbances was assessed by standardized questionnaires and validated scales in 18 patients with A53T PD and 18 patients with tPD, matched for age, sex, and disease duration.
Since the first discovery of a specific genetic defect in the SNCA gene, encoding for α-synuclein, as a causative factor for Parkinson's disease 20 years ago, a multitude of other genes have been linked to this disease in rare cases with Mendelian inheritance. Furthermore, the genetic contribution to the much more common sporadic disease has been demonstrated through case control association studies and, more recently, genome-wide association studies. Interestingly, some of the genes with Mendelian inheritance, such as SNCA, are also relevant to the sporadic disease, suggesting common pathogenetic mechanisms.
View Article and Find Full Text PDFIntroduction: The p.A53T point mutation in SNCA, the alpha-synuclein gene, has been linked to a rare dominant form of Parkinson's disease (PD).
Methods: Here, we describe two apparently unrelated cases of p.
Background: G209A SNCA mutation carriers represent an important group of genetic PD. We describe motor and nonmotor features of G209A SNCA mutation carriers.
Methods: Longitudinal clinical assessments over 2 years were collected in 22 symptomatic and 8 asymptomatic G209A SNCA mutation carriers.
Background: We sought to evaluate the potential enhanced fibrinolytic and antiplatelet activity of dabigatran etexilate (DE) due to decreased thrombin levels in patients with stroke or transient ischemic attack and non-valvular atrial fibrillation (NVAF).
Methods: Consecutive patients with cerebrovascular diseases and NVAF that were treated with DE in a tertiary university hospital. Fibrinolysis and platelet function were assessed by thromboelastometry (ROTEM) and platelet function analyzer (PFA)-100, respectively, before and after treatment with DE.