Ch 3-genetics & epigenetic Flashcards
(20 cards)
What is the polygenicity of mental illness?
Psychiatric disorders involve thousands of common genetic variants with small individual effects, requiring genome-wide association studies (GWAS) with >100,000 participants for reliable detection.
This highlights the complexity of genetic influences on mental health.
What is the significance of shared genetic architecture in major psychiatric disorders?
Major psychiatric disorders (schizophrenia, bipolar, depression) show extensive genetic overlap, challenging traditional diagnostic boundaries.
This suggests that these disorders may share underlying biological mechanisms.
What are DNA methylation signatures linked to?
Site-specific methylation changes in synaptic genes (e.g., BDNF, SLC6A4) are linked to depression, suicide, and stress responses.
Methylation can affect gene expression and contribute to mental health outcomes.
How does chronic stress affect histone modification in neurons?
Chronic stress reduces histone acetylation in hippocampal neurons, while antidepressants restore it via HDAC inhibition.
This illustrates the potential for treatment to reverse stress-induced epigenetic changes.
What are transgenerational epigenetic effects?
Parental trauma/exposure to toxins can induce heritable epigenetic changes increasing offspring vulnerability to psychopathology.
This highlights the long-term impact of environmental factors on mental health.
How does prenatal air pollution exposure affect autism risk?
Prenatal air pollution exposure induces methylation changes in neurodevelopmental genes, correlating with 3× higher autism risk.
This emphasizes the role of environmental factors in neurodevelopment.
What do protective factors do in epigenetic resilience mechanisms?
Protective factors (social support, enrichment) activate DNA repair genes like OGG1 through demethylation, counteracting stress effects.
This indicates potential avenues for promoting resilience in mental health.
What role do neuroinflammation pathways play in mental health?
Methylation of IL-6 and TNF-α promoters mediates the link between childhood adversity and adult depression.
This suggests that inflammation may be a key biological mechanism linking early life stress to later mental health issues.
What is cross-tissue epigenetic consistency?
Peripheral blood methylation patterns in NR3C1 (glucocorticoid receptor) mirror brain changes in PTSD patients.
This could provide a non-invasive biomarker for PTSD.
What is pharmacoepigenetics?
SSRI response correlates with methylation status of SLC6A4 and ABCB1 genes, enabling personalized dosing.
This highlights the potential for tailoring psychiatric treatment based on genetic profiles.
What percentage of schizophrenia cases are accounted for by SWI/SNF mutations?
SWI/SNF mutations account for 5-10% of schizophrenia cases through dysregulation of synaptic pruning genes.
This indicates a specific genetic contribution to the disorder.
How does mitochondrial epigenetics affect bipolar disorder?
Methylation of mitochondrial DNA (e.g., MT-ND5) impairs energy metabolism in bipolar disorder patients.
This suggests that mitochondrial function may be disrupted in mood disorders.
What is the effect of CLOCK gene hypermethylation in depression?
CLOCK gene hypermethylation in depression alters HPA axis dynamics and sleep architecture.
This points to the connection between circadian rhythms and mood regulation.
What explains the 2:1 female predominance in anxiety disorders?
X-chromosome inactivation patterns explain 2:1 female predominance in anxiety disorders.
This highlights the role of sex chromosomes in mental health disparities.
What is the impact of LINE-1 hypomethylation in schizophrenia?
LINE-1 hypomethylation in schizophrenia increases retrotransposon activity, causing genomic instability.
This suggests a mechanism by which genetic instability may contribute to the disorder.
What do advanced epigenetic clocks predict in treatment-resistant depression?
Advanced epigenetic clocks (GrimAge) predict 68% of treatment-resistant depression cases.
This indicates the potential for epigenetic markers to inform treatment strategies.
What effect does folate deficiency have on methylation?
Folate deficiency induces hypermethylation of MTHFR, disrupting monoamine synthesis pathways.
This suggests dietary factors could influence mental health through epigenetic mechanisms.
How does 3D genome restructuring affect bipolar disorder?
3D genome restructuring in GABAergic neurons mediates lithium’s anti-manic effects in bipolar disorder.
This highlights a potential biological target for therapeutic intervention.
What shared methylation patterns implicate oligodendrocyte dysfunction?
Shared methylation patterns in SOX10 and OLIG2 implicate oligodendrocyte dysfunction across psychosis spectrum disorders.
This suggests common pathways in various psychotic disorders.
What is the therapeutic reversibility demonstrated by Vorinostat?
Vorinostat (HDAC inhibitor) restores fear extinction memory in PTSD models through CREB-binding protein acetylation.
This demonstrates the potential for epigenetic therapies in mental health treatment.
