PSYCH 2AP3 Lecture Notes - Lecture 10: Small Arms, Candidate Gene, Manganese
- Not a constant:
o Varies across populations
o Varies across time in any population Heritability of ADHD
• - ADHD runs in families – more for girls than boys
• - Heritability based on parent ratings
o .60 - .90 (less for teacher ratings)
Gene Searches
- Candidate gene approach:
September 28, 2017
Gene Search Results o 5p12
▪
o 7p13 ▪
10q26 12q23 →first round testing
9q33 13q33 →second round testing
16p13 15q15
• - Small arm of each chromosome→P ARM
• - Long arm of each chromosome→Q ARM
• - 5p23
lOMoARcPSD| 2151316
o Search for link between theoretically interesting genes and disorder o Most common approach
▪ Linkage studies
• Look at the incidences of a particular disorder within a connected
family
o See if there is a correlation
▪ Association studies
• Take people who have the symptoms of a disorder, look at a
genome, and look at people and their genomes without the disorder o See if there’s a difference
Document Summary
Not a constant: varies across populations, varies across time in any population heritability of adhd. Adhd runs in families more for girls than boys. Heritability based on parent ratings: . 60 - . 90 (less for teacher ratings) Gene search results o 5p12: 7p13 . Can study people without disorder, but with same endophenotype. Good if disorder is polygenic: multiple genes involved. Good if disorder has several different causal paths. Good if several disorders share same endophenotype learn about both simultaneously. Temperament and adhd - extraversion: based on dopaminergic circuits, dysfunctional reward circuitry in adhd, some indication that there is a negative relationship between extroversion and adhd. Neuroticism: tendency towards negative emotion o related to limbic reactivity to stress. Conscientiousness: related to executive functions, high in phi low in conscientiousness. Low birth weight o premature: associated with higher levels of multiple mental disorders. Pre- and post-natal toxin exposure: mercury; manganese; lead.