1.   Children who inherit the defective gene seem normal at birth apart from a deformity of the toe.

2.   The disease is caused by a defective gene.

3.   While it strikes men twice as often, women can also carry the defective gene and pass it along to their children.

4.   Girls in an affected family can also be tested to see if they carry the defective gene.

5.   The illness is caused by a defective gene and can affect all parts of the body, but the lungs are most vulnerable.

6.   Now they think they can cure the defective gene in the lungs.

7.   There it will take over from the defective gene and form the right combination to allow fluids to leave the cells normally instead of collecting into a mucous.

8.   Research on the family has enabled scientists to identify a defective gene responsible for causing the disease.

9.   And all because they carry two copies of a defective gene.