Multifactorial Inheritance/ Epigenetics

Question 1

• MF inheritance def?
• What plays a role?
• Ex? (9)
• Experiments looking at this?

Answer 1

• Relatives have increased risk but no consistent pattern of inheritance
• Multiple genes and environment play a role
• T1D, T2D, Alzheimers, IBD, Schizophrenia, Cleft Lip, Hypertension, Arthritis, Asthma
• Twins, Adoptions, Immigration

Question 2

• Characteristics of complex trait? (4)

- Heritiability def? Increased heritability means? Ex:

Answer 2

• incomplete penetrance, variable expressivity, allelic and genetic heterogeneity, phenocopies (people have disease for reasons not necessarily genetic)
• Proportion of disease variation due to genetics trait; difference largely due to genes. Example: looking at how much genes play a role in height of a population

Question 3

• Charatacteristics of epigenetics? (4)
• Analogies used to explain this? (2)
• Best example of epigenetics?
• 4 other examples?

Answer 3

• Different expression from same genome, inheritance through cell division (feast vs. famine example), on/off switch, erasable which is important b/c gene therapy is so tough
• Waddington’s boulder, lights board
• Stem cells –> different adult cells
• demethylation, methylation, maintenece methyl transferase after somatic cell division, packaing DNA into chromatin

Question 4

• H3 modification that occurs?
• Inheritance state of H3?
• Non-nuclear epigenetics with cancer?
• Silencing with tumor supressor gene? Possible treatment?

Answer 4

• Repress = methylation; activate = acetylation
• H3 modified post replication
• Switch involving NfKb
• With age, TSG is methylated and eventually silenced; lung cancers myeloid neoplams treated with DNA methyl transferase and deacetyl transferase inhibition to turn on TSG