Lecture summary Qs

Question 1

What are polygenic traits

Answer 1

Traits that are affected by more than 1 gene

Question 2

What are quantitative MFIs

Answer 2

Ones that can be measured on a scale

Question 3

What are threshold MFIs

Answer 3

Ones that are (threshold passed) all or nothing

Question 4

How can you determine the recurrence risk of MFI traits

Answer 4

square rot of the incidence of the trait

Question 5

What is the overall recurrence risk of any given trait

Answer 5

4%

Question 6

What family hx suggests gonadal mosaicism

Answer 6

Negative family hx for disease but 2+ offspring with it

Question 7

How do gonadal mosaicisms come about

Answer 7

de novo mutations

Question 8

What is genomic imprinting and give example(s) of diseases in this category

Answer 8

Epigenetic modifications of the zygote. Some traits/genes are more likely to be passed on by one parent. Prader-Willi and Angelman syndromes

Question 9

Prader-Willi syndrome characteristics and causes

Answer 9

lack of expression in paternal allele. Can be the result of maternal UPD or paternal deletion

Question 10

Angelman syndrome characteristics and causes of Angelman’s syndrome

Answer 10

Lack of expression of maternal allele. Can be result of paternal UPD or maternal deletion

Question 11

What is anticipation

Answer 11

The increase in severity of a disorder in proceeding generations

Question 12

what is a premutation

Answer 12

just like it sounds–last stage in anticipation before mutation or trait becomes expressed