Pre-clinical medicine
Medical genetics
Medical genetics studies how genes and chromosomes cause or influence disease, and how genetic conditions are diagnosed and counselled. Many psychiatric disorders are partly heritable, and some genetic syndromes have characteristic psychiatric features.
Depth by stage, Pre-U → Consultant (details)
What is it?
Medical genetics covers single-gene disorders, chromosomal abnormalities, complex (multifactorial) inheritance, genetic testing and genetic counselling.
Students learn to draw family trees, calculate risk in simple cases, and understand how genes interact with the environment.
Newer areas include genomics and pharmacogenetics, the study of how genetic differences change how people respond to medicines.
Why does a psychiatrist need it?
Conditions such as schizophrenia, bipolar disorder and autism run in families, though usually through many genes of small effect plus environment. Families often ask psychiatrists about the risk to children. Some genetic syndromes, such as Down syndrome, fragile X and 22q11.2 deletion syndrome, carry known psychiatric risks. Pharmacogenetics may increasingly guide drug choice.
What level is expected at each stage?
Scale: 1. Aware → 2. Understands → 3. Applies → 4. Masters / Teaches. What the levels mean.
- Pre-UAwareAware of basic inheritance from school biology.
- Pre-clinicalUnderstandsUnderstands inheritance patterns, chromosomal disorders and genetic testing.
- ClinicalAwareAware of genetic conditions encountered in paediatrics and O&G.
- HousemanshipAwareAware; background knowledge.
- Medical officerAwareAware; background knowledge.
- Psych traineeUnderstandsUnderstands psychiatric genetics: twin and family studies, polygenic risk, key syndromes.
- Specialist / consultantUnderstandsUnderstands enough to counsel families on general risk and refer for genetic services.
What are the key topics?
Inheritance patterns
- Autosomal dominant and recessive
- X-linked inheritance
- Mitochondrial inheritance
- Pedigree drawing and risk estimation
Chromosomes
- Down syndrome (trisomy 21)
- Sex chromosome conditions such as Turner and Klinefelter
- Microdeletions such as 22q11.2
- Karyotyping and microarray testing
Complex genetics
- Multifactorial inheritance and heritability
- Gene-environment interaction
- Genome-wide association studies (introduction)
- Epigenetics (introduction)
Clinical genetics
- Genetic counselling principles
- Prenatal and newborn screening
- Ethical issues in genetic testing
- Pharmacogenetics, including CYP450 variation
How is it learned and assessed?
- Lectures and PBL, often within other blocks
- MCQ and short-answer exams, including pedigree problems
- Psychiatric genetics revisited in specialist basic sciences exams
Typical textbooks and resources
- Emery's Elements of Medical Genetics — Elsevier
- Medical Genetics at a Glance — Wiley-Blackwell
- Thompson and Thompson Genetics in Medicine — Elsevier
- New Clinical Genetics — Read and Donnai (Scion)
Titles are widely used examples; editions change. Use university libraries or legitimate purchases.
Common questions
Is mental illness genetic?
Partly. Many conditions are more common in families, but genes raise risk rather than decide it. Environment, life events and chance also play large roles, so most children of affected parents do not develop the same illness.
Can a genetic test diagnose depression or schizophrenia?
No. There is currently no genetic test that diagnoses common psychiatric disorders. Genetic testing is used mainly for specific syndromes, such as in children with intellectual disability.