Two unaffected parents each have a parent with the same recessive condition and they want to know the chances that they will have a child who has the condition. What do you tell them?

Question

Quizplus · Accepted Answer

Since both parents are unaffected but have a parent with a recessive condition, it implies they are carriers (heterozygous) for the recessive gene. When two carriers mate, the Mendelian inheritance pattern gives a 25% chance for an offspring to be affected (homozygous recessive).

Two Unaffected Parents Each Have a Parent with the Same