Question : A woman with cystic fibrosis ,an autosomal recessive condition marries her first cosin.What is the risk that their first childwill have cystic fibrosis ?

Question : A woman with cystic fibrosis ,an autosomal recessive condit

1.	Question : A woman with cystic fibrosis ,an autosomal recessive condition marries her first cosin.What is the risk that their first childwill have cystic fibrosis ?
Answer» `1//4` `1//2` `3//4` `1//8` Solution :The gentoype of affected woman is cc. Her parents are obligate carries (Cc) and ONE of her grand parents must also be a carrier. Her FIRST cousin then has a 1/4 CHANCE being a carrier.He has 1/2 chance of transnmitting his c allete if it is present.So the chance of CHILD being a PATIENT of cystic fibrosis is `1//4xx1//2=1//8`