Genetics, Epigenetics, Neurodevelopment and Plasticity
Genetic methods and architecture, epigenetic mechanisms, neural development, critical periods, experience, injury and therapy-related plasticity.
How to prepare for MRCPsych Paper A
Build mechanisms first, connect them to development and assessment, then practise distinguishing one best answer within SBA and extended-matching formats.
Core concepts
Concept 1
Psychiatric traits commonly have polygenic, pleiotropic and heterogeneous architectures shaped by gene–environment correlation and interaction.
Exam cue: Separate variant association, statistical liability and mechanism before making a clinical inference.
Concept 2
Epigenetic regulation, neurodevelopment, critical periods and lifelong plasticity connect inherited variation and experience without implying that acquired marks or outcomes are fixed.
Exam cue: Locate an exposure in developmental time and ask which cells, circuits and compensatory processes are affected.
Risk pitfalls and guardrails
Calling a common risk variant a diagnostic gene or a sufficient cause.
Guardrail: Do not turn a score or group association into certain prediction for an individual.
Treating epigenetics as a vague synonym for any environmental effect.
Guardrail: Do not select an option because it is merely associated or familiar; choose the one that answers the exact lead-in.
Memory anchors
What does polygenic mean?
Many genetic variants each contribute small effects to variation in liability or a trait.
What is pleiotropy?
One genetic variant or biological pathway influences more than one trait or outcome.
How do gene–environment interaction and correlation differ?
Interaction means an effect differs by environment; correlation means genetic factors influence exposure to environments.
What is epigenetic regulation?
Heritable-through-cell-division changes in gene activity that do not alter the DNA sequence, including DNA and chromatin modifications.
What is a critical or sensitive period?
A developmental window when particular experience has an unusually strong or necessary effect on a system.
Checkpoint rule
Do the check-up only after you can summarize each concept in one sentence and identify one dangerous pitfall from memory.
Knowledge Check (after reading)
Short check-up to confirm understanding of this module.
Check-up Questions
How many autosomes are present in a normal human somatic cell?
Which cell division produces two genetically similar diploid daughter cells?
Answer all questions to submit.
Next step personalized recommendations
Continue learning
Move forward only after this module is stable.
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