EB - Risk factors of metal health disorders I Flashcards
Why do people suffer from neuropsychiatric disorders? (2)
- Risk; involves uncertainty and vulnerability/sensitivity.
- Genetic factors; a critical determinant.
What genetic models are used for understanding disease risk and why are they useful? (3)
Family diagrams:
Family studies
- Identify families with higher disease incidence.
- Measure recurrent risk ratio; the increased risk of a disease occurring in a relative of an affected individual compared to the general population
Twin studies
- MZ vs DZ
- Higher concordance in monozygotic twins suggests genetic contribution.
Linkage studies:
- Identify regions of the genome linked to disease inheritance
- Effective for Mendelian disorders.
- Less useful for polygenic conditions.
What are association studies, and how do they work? (4)
Candidate Gene Studies:
- Focus on specific genes linked to disease.
- Compare genetic variant frequencies in cases vs. controls.
Genome-Wide Association Studies (GWAS):
- Scan the genome for disease-linked variants.
- Effective for common variants with small effects.
Structural Variation Studies:
- Examine copy number and structural variations.
Sequencing Studies:
- Detect rare variants with large effects.
What are Gene-Environment Interaction (GxE) Studies? (2)
- Study genetic and environmental factor interplay in disease risk.
- Identify individuals at higher risk based on combined exposures.
What are Functional Studies in molecular genetics?
- Explore how genetic variants influence disease mechanisms.
- Investigate:
Gene expression.
Protein function.
Cellular pathways.
How are Animal Models used in genetic research? (2)
- Study genetic variant effects on disease progression.
- Example: Use mice to simulate human genetic conditions.
What are Clinical Studies, and what do they examine? (4)
- Investigate clinical implications of genetic findings.
Focus areas:
- Diagnostic test development.
- Prognostic marker identification.
- Creation of targeted therapies
What is the importance of Pathway Analysis? (2)
- Determines if genetic variants act within the same pathways.
- Identifies biological pathways influencing disease mechanisms.
What are the two types of mutations?
- Inherited variations: Passed through generations.
-
De novo mutations: New mutations linked to paternal age.
The number of de novo mutations in the person’s genome increases with paternal age
How does the timing of mutations affect cell impact? (5)
Parental gonad: All offspring cells affected.
Early embryo: Large proportion affected.
Embryo: A smaller portion of the offspring’s cells will carry the mutation
Fetus: An even smaller portion of the offspring’s cells will carry the mutation.
Post-birth: Tissue-specific effects.
What is penetrance in genetics? (3)
- Proportion of individuals with a genetic variant showing the phenotype.
- Inversely related to allele frequency
- Example: Huntington’s disease has 100% penetrance with triplet expansion.
What is linkage disequilibrium (LD)? (3)
- Non-random association of nearby alleles on a chromosome.
Causes:
- Genetic Linkage: Close alleles likely inherited together.
- Population History: Influences LD patterns.
What is the evidence for heritability? (4)
Monozygotic twin studies: Concordance rates for:
- Autism: 80%–90% (MZ) vs. 5%–15% (DZ).
- Monozygotic to dizygotic twin concordance ratios for drug addictions are approximately 2:1
- Psychiatric disorders: Highly polygenic.
- There are common variants with small effect sizes.
What are the three groups of genetically related psychiatric disorders identified by GWAS?
- Mood/Psychotic: Depression, bipolar, schizophrenia.
- Neurodevelopmental: Autism, ADHD, OCD.
- Compulsive Behaviors: Anorexia, Tourette’s.
What are GWAS challenges? (3)
- Sample size; small effect sizes, making them difficult to detect with smaller sample sizes.
- Sample ancestry; Different populations may have different genetic risk factors
- Disease definition; a lot of diagnosis is based on self reporting of specific traits
