One parent is heterozygous for a certain known disease and is unaffected.The other parent is homozygous normal.Under which circumstance would DNA testing be of value for their newborn son to ensure he does not suffer complications due to the disease?

Question

Quizplus · Accepted Answer

If the disease is X-linked, the son inherits one X chromosome from the heterozygous mother and one Y chromosome from the father. As he only has one X chromosome, if the disease is present on that X chromosome, he will be affected. DNA testing can determine whether the son has inherited the X chromosome with the disease or not.

One Parent Is Heterozygous for a Certain Known Disease and Is