11) Genetics of Mood Disorders

Question 1

How can it be determined if a condition is genetic?

Answer 1

Family studies
Twin studies
Adoption studies
Sex differences 
Linkage/association

Question 2

What are the problems in reviewing literature relating to depression?

Answer 2

Lack of biological measure of diagnosis

Question 3

What do family studies show about depression and bipolar?

Answer 3

Both are inherited
Bipolar leads to increase in BP and depression
Depression leads to increase in depression but not BP

Question 4

What do twin studies show about depression and bipolar?

Answer 4

Monozygotic twins very likely to both have bipolar, and quite likely to both have depression when compared with dizygotic twins

Question 5

What do adoption studies show about inheritance of depression?

Answer 5

More likely to be affected if biological parents were affected

Question 6

What are the two main forms of inheritance in affective disorders?
Hint: SML and QTL

Answer 6

Single major locus

Quantitative trait loci - multiple alleles affecting phenotype

Question 7

What is linkage?

Answer 7

Co-occurrence of a known disease and know location

Question 8

What is association?

Answer 8

Co-occurrence of an allele at a particular locus and a disease

Question 9

What are some genes implicated in depression?

Answer 9

Serotonin transporter gene (chromosome 17)
BDNF gene (chromosome 11)

Question 10

What are copy number variants?

Answer 10

Sections of genome that are repeated

Question 11

How are CNVs affected in depression?

Answer 11

Increased