Autosomal (dominant and recessive) Inheritance

Question 1

If two unaffected parents have an affected child, what might be the recurrence risk in a second child if the disease is autosomal recessive?

Answer 1

25% - every time this couple mates there is a 25% chance the child will be affected

Question 2

Can women have the possibility of one the 3 different genotypes being expressed in their sex chromosome?

Answer 2

Yes - males cannot since they have to X to match

Question 3

What is different about H/W for males in x-linked diseases?

Answer 3

Allele frequency = genotype frequency

q = prevalence of the trait in males NOT q^2

Question 4

Consultand

Answer 4

seeks the genetic advice but does not actually have the disease

Question 5

Proband

Answer 5

has the disease and brought it to attention

Question 6

What kind of genetic disease almost never has homozygotes?

Answer 6

Autosomal dominants

Question 7

When you see inbreeding you should think…

Answer 7

Recessive diseases

Question 8

What do we know about the parents of a sickle cell baby?

Answer 8

They are obligate carriers

Question 9

T or F: affected offspring are considered carriers?

Answer 9

False

Question 10

What is the order of risk in genetic disorders?

Answer 10

Familial Risk (w/ + fam. history) > at risk population> general population

Question 11

What is the lowest risk in any genetic disorder?

Answer 11

the risk presented in the general population = baseline risk