👤 Jesús Montoya

Major Depressive Disorder (MDD) is a multifactorial psychiatric disease influenced by a combination of genetic and environmental factors. Among the genes linked to MDD, the Melanocortin 1 Receptor (MC1R), Catechol-O-Methyltransferase (COMT), Brain-Derived Neurotrophic Factor (BDNF), and the serotonin transporter (5-HTT) are of particular interest due to their critical roles in stress regulation and neural function. Despite their biological significance, the contribution of specific polymorphisms within these genes to MDD risk remains understudied. This retrospective observational case-control study included 87 Colombian patients diagnosed with MDD according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). The control group comprised Latino/admixed individuals without, sourced from the gnomAD v2.1.1 database. The complete coding region of the MC1R gene and three polymorphisms: 5-HTTLPR Insertion/Deletion 44 bp, BDNF-c.196G>A, and COMT-c.472G>A were genotyped using PCR and Sanger sequencing. The polymorphisms rs885479 and rs4680 were identified as protective factors against MDD, while the polymorphisms rs796296176, rs779504604, rs1805005 were associated with an increased risk of developing MDD (OR:22.87, OR:51.26, OR: 1.97, respectively). Several of the analyzed polymorphisms (rs796296176, rs779504604, rs1805005) increase the risk for MDD. Notably, we provide novel evidence of these polymorphisms in MC1R as a risk to MDD. Show less

Previous reports of distal deletions in chromosome 10q in patients have described distinct facial features combined with other neurodevelopmental abnormalities, including intellectual disability. However, the association of interstitial deletions in chromosome 10q with global developmental delay, musculoskeletal abnormalities, and dysmorphic features has not been previously reported. Genetic testing using whole exome sequencing (WES) was performed on three patients with neurodevelopmental delay, musculoskeletal abnormalities and dysmorphic features. Sequencing reads were aligned to the human genome build GRCh37/UCSC hg19 and analysed for both sequence and copy number variants. WES identified similar interstitial deletions in the 10q21.1q21.3 locus in all three patients. The deleted region includes online Mendelian inheritance in man (OMIM)-annotated genes with clinical significance, such as This is the first report associating interstitial deletions in the 10q21.1q21.3 locus with neurodevelopmental delay, musculoskeletal abnormalities and dysmorphic features. Our findings highlight the clinical significance of this deleted region and suggest possible mechanisms underlying the observed pathological phenotypes. Show less

Variants close to the VPS13C/C2CD4A/C2CD4B locus are associated with altered risk of type 2 diabetes in genome-wide association studies. While previous functional work has suggested roles for VPS13C and C2CD4A in disease development, none has explored the role of C2CD4B. CRISPR/Cas9-induced global C2cd4b-knockout mice and zebrafish larvae with c2cd4a deletion were used to study the role of this gene in glucose homeostasis. C2 calcium dependent domain containing protein (C2CD)4A and C2CD4B constructs tagged with FLAG or green fluorescent protein were generated to investigate subcellular dynamics using confocal or near-field microscopy and to identify interacting partners by mass spectrometry. Systemic inactivation of C2cd4b in mice led to marked, but highly sexually dimorphic changes in body weight and glucose homeostasis. Female C2cd4b mice displayed unchanged body weight compared with control littermates, but abnormal glucose tolerance (AUC, p = 0.01) and defective in vivo, but not in vitro, insulin secretion (p = 0.02). This was associated with a marked decrease in follicle-stimulating hormone levels as compared with wild-type (WT) littermates (p = 0.003). In sharp contrast, male C2cd4b null mice displayed essentially normal glucose tolerance but an increase in body weight (p < 0.001) and fasting blood glucose (p = 0.003) after maintenance on a high-fat and -sucrose diet vs WT littermates. No metabolic disturbances were observed after global inactivation of C2cd4a in mice, or in pancreatic beta cell function at larval stages in C2cd4a null zebrafish. Fasting blood glucose levels were also unaltered in adult C2cd4a-null fish. C2CD4B and C2CD4A were partially localised to the plasma membrane, with the latter under the control of intracellular Ca Our studies suggest that C2cd4b may act centrally in the pituitary to influence sex-dependent circuits that control pancreatic beta cell function and glucose tolerance in rodents. However, the absence of sexual dimorphism in the impact of diabetes risk variants argues for additional roles for C2CD4A or VPS13C in the control of glucose homeostasis in humans. The datasets generated and/or analysed during the current study are available in the Biorxiv repository ( www.biorxiv.org/content/10.1101/2020.05.18.099200v1 ). RNA-Seq (GSE152576) and proteomics (PXD021597) data have been deposited to GEO ( www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE152576 ) and ProteomeXchange ( www.ebi.ac.uk/pride/archive/projects/PXD021597 ) repositories, respectively. Show less