Question

82 GENETICS LABORATORY MANUAL 4. Cystic fibrosis is one of the most common autosomal recessive diseases in people Northern European descent. A mutation in the CF gene affects a protein involved in the transport of chloride and sodium across cell membranes, causing thick mucus and secretions, lung damage, and nutritional deficiencies. The disease is inherited in an autosomal recessive manner, meaning one must inherit two mutated alleles in order to have the disease. Greg does not have cystic fibrosis, and there is no family history of the disease. His wife Sally also does not have cystic fibrosis, but her sister does. As a genetic counselor, what would you tell Greg and Sally about the probability of their children inheriting cystic fibrosis? In your explanation, include the possible genotypes for both Greg and Sally.

Answer 1

Cystic fibrosis  is an inherited disease which leads to severe damagesto lungs, digestive system and various other organs in the body.  

As Greg doesnot have any case history of this disease but his wife Sally has this disorder in her inheritance because her sister is affcted with this Cystic Fibrosis. This implies that Sally must be a carrier of the disease. As when taking into acount the history of Sally parents they must be carriers of this disease. Now considering the case of Greg and Sally when they have offsprings their is no chance that any of the children will develop this effect. However, 50% chances that they have normal chidrens and 50% chances that the children become carriers like their mother but, the complete symptoms will never be shown by any of them.