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A single nucleotide polymorphism in the brain derived neurotrophic factor (BDNF)-encoding gene leads to diminished BDNF signaling resulting from Val66Met and has been linked to obesity. Previous imaging studies regarding the impact of BDNF Val66Met on the central serotonin system, which is involved in behavior, cognition and control of satiety, have not focused on body weight or food-intake related behavior. We revisited a cohort of thirty non-depressed individuals with obesity and 15 normal-weight controls. 29 obese and 13 controls underwent [ Show less

Conflicting results on the association of the Using combinations of various key terms, articles in PubMed, Google Scholar, and Web of Science, written in English were collected until October 31, 2024. Data were extracted independently by two authors and analyzed using Review Manager 5.4. Fifteen studies that are compliant with the HWE, providing a total of 14,184 participants were included in this meta-analysis after applying predefined inclusion/exclusion criteria based on study design, DSM-based diagnosis, and availability of genotype counts. Most pooled models demonstrated low to moderate heterogeneity with significant associations in the recessive model only. In the subgroup analysis, a significant effect was observed in the PD-uncategorized cohort. The Our updated meta-analysis suggests that the Show less

Major depressive disorder (MDD) is a prevalent and disabling psychiatric condition in Saudi Arabia, with genetic susceptibility remaining incompletely characterized. Reduced brain-derived neurotrophic factor (BDNF) activity has been implicated in MDD. The Val66Met polymorphism (rs6265), involving the substitution of valine (Val, G allele) with methionine (Met, A allele), impairs activity-dependent BDNF secretion. This study examined the frequency of Val66Met and its association with MDD in a Saudi cohort. A case-control study was conducted, including 87 patients with MDD (44 males, 43 females; mean age 44.2 ± 11.5 years) and 87 healthy controls (39 males, 48 females; mean age 28.7 ± 8.4 years). Genotyping was performed using tetra-primer amplification refractory mutation system-polymerase chain reaction. Unadjusted and age- and sex-adjusted logistic regression analyses were applied under genotype-specific, dominant, recessive, and allelic models. The Val/Val (GG) genotype was more frequent in controls than patients (54.0% vs. 34.5%), whereas the Met/Met (AA) genotype was detected exclusively in patients (21.8% vs. 0%; χ The BDNF Val66Met polymorphism is associated with MDD susceptibility in Saudis. The Met (A) allele, particularly in homozygosity, confers increased risk, while the Val/Val genotype appears protective, supporting population-specific genetic contributions to depression. Show less

Brain-derived neurotrophic factor (BDNF) has been suggested to support dopaminergic neuron's endurance and dopamine release. Its Val66Met polymorphism might modify Parkinson's disease (PD) evolution, although evidence in Asian populations remains limited. This study aimed to explore how the BDNF rs6265 genotypes are associated with the clinical characteristics and longitudinal progression patterns of PD patients in a Korean population. A total of 247 patients were enrolled and followed for a mean duration of 50.9 ± 23.9 months. Baseline and/or periodic assessments captured motor severity, non-motor burden, cognition, orthostatic stress, cardiac denervation, and presynaptic dopamine transporter availability. The repeated measures were manipulated to infer any genotypic differences in the trajectories of each clinical domain. Genotype frequencies were 31.2% (77/247) for Val/Val and 68.8% (170/247) for Met-allele carriers. Baseline clinical characteristics and presynaptic dopamine transporter availability were comparable between genotypes; however, Val homozygotes showed more preserved myocardial innervation and poorer non-frontal cognitive performance. Longitudinal analyses demonstrated genotype-specific increases in motor and cognitive severity. Compared to Met-allele carriers, the homozygous Val group exhibited accelerated motor progression and more rapid decline in frontal domain after three years of follow-up. The differences in myocardial denervation at diagnosis, cognitive profiles, and motor progression might suggest a potential modulatory role of BDNF polymorphism in PD progression in the Korean population. Show less