Question

Located on chromosome #4

Autosomal dominant

Adults have shortened limbs and may experience joint paint, increased ear infections and sleep apnea

The average male is 52 inches in height and the average female is 48 inches in height as an adult

Life span for most individuals is decreased by 10 years

If both parents pass on a mutant gene, babies may only live for a couple of months

Both parents are heterozygous for the trait.

What is the mother’s genotype (indicate with letters)?

What is the father’s genotype (indicate with letters)?

Draw a Punnett Square in the space below

How many of the offspring would be afflicted with the inherited condition?

Given the condition background provided, what do you suggest the couple do?

Answer 1

For autosomal dominant traits -

Normal = aa

Affected = AA, Aa

In the question, both the parents are heterozygous, Aa.

Father = Aa

Mother = Aa

Aa × Aa

Gametes	A	a
A	AA affected	Aa affected
a	Aa affected	aa normal

Proportion of affected individuals = 3/4 = 75%

Since there are more chances that the progeny will be affected, I will suggest the couple to go for the complete genetic analysis of the baby within the first trimester of pregnancy and if the baby is affected, then they should abort the child.

Please give a good rating.