Cystic fibrosis is inherited as an autosomal recessive condition. A normal couple has one daughter affected with the disease. They are now planning to have another child. What is the chance of her sibling being affected by the disease
O
1\/2
1\/4
3\/4
Robbins basic pathology 9th edition page no 220, heading=disorders of Autosomal recessive inheritance Siblings have one chance in four of being affected. Therefore the chance of the sibling being affected according to the question is 1/4.
General pathology