Why study genetic disorders?
- Clinical practice - identify disorders, HGP.
- Theory - unique opportunity to see what genes do. Pinker (2001) ‘dawn of cognitive genetics’.
What is the prevalence of phenylketonuria, what is it, and what gene is it caused by?
- 1 in 10,000
Define autosomal.
Genetic but not linked to sex chromosomes.
What is the prevalence of Huntington’s Disease, what is it, and what gene is it caused by?
- 1 in 10-20,000
What is phenylketonuria?
Metabolic disorder which untreated can result in mental retardation and seizures - used to be responsible for 1% of hospitalised cases of learning disability.
What is the cause of phenylketonuria?
- Malfunction in the pathway producing the amino acid tyrosine.
- Autosomal recessive disorder on chromosome 12
What is Huntington’s Disease?
Characterised by involuntary movements, personality changes and forgetfulness becoming noticeable around the age of 40.
What is the cause of Huntington’s Disease?
- Due to progressive damage of the basal ganglia and cortex
- Autosomal dominant, chromosome 4.
What are sporadic mutations?
Mutations that occur in the individual - they aren’t inherited from parents. They are usually due to errors in segregation when gametes are produced.
What are examples of sporadic mutation genetic disorders?
Down’s syndrome and William’s syndrome.
What is Down’s syndrome?
- Symptoms include facial dysmorphology, short stature and learning difficulties.
- IQ usually around 55, but performance and cognitive profile vary.
What is the prevalence of Down’s syndrome?
- 1 in 1,000 but increases with age of parents
What is the cause of Down’s syndrome?
- Abnormality in chromosome numbers
- Majority due to trisomy of chromosome 21.
What is William’s syndrome?
- Symptoms include low IQ (50-70) and some facial dysmorphology.
- Also an uneven profile of cognitive abilities (of great interest): dissociation between language and general cognitive abilities.
What is the prevalence of William’s syndrome?
Approx. 1 in 2,000.
What is the cause of William’s syndrome?
- Microdeletion on chromosome 7
Why are X-linked disorders easier to detect?
Because they’re inherited differently for males and females.
What was the first reported case of X-linkage?
Colour blindness
What disorders are caused by changes in the number of X chromosomes?
Turner’s syndrome and Klinefelter syndrome.
What is the cause and prevalence of Turner’s syndrome?
- X0
- 1 in 2,500 births (women only).
What are the symptoms of Turner’s syndrome?
- Short stature
- Infertility
- Verbal IQ normal, performance IQ can be a bit lower.
What is the cause and prevalence of Klinefelter syndrome?
- X(+)XY
- 1 in 750 births (men only)
What are the symptoms of Klinefelter syndrome?
- Hormone imbalances (treatable)
- Below average IQ.
- Speech and language difficulties.
- Breast development, poor beard growth, long legs and wide hips.
What is Fragile X syndrome caused by?
A single gene dysfunction on the X chromosome.
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How to study the brain28
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Evolution24
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Transmission between neurons23
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Transmission within a neuron (action potentials)24
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Vision: Primary visual pathway35
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Visual perception and memory: Occipital and temporal lobe22
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The parietal and frontal lobes28
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Emotion30
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Brain anatomy and organisation44
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Introduction to Learning 1 and 225
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Introduction to genetics16
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Genetic disorders26
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Sleep30
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Sex and stress31
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Eating and appetite25
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Introduction to cognitive neuropsychology and the cognitive neuropsychology of language17
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Introduction to the neuropsychology of memory & perception34
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Schizophrenia and affective disorders25
