How can you get cystic fibrosis?

Cystic fibrosis is a genetic disease and can only be inherited through genes.

It all depends on your parents alleles. Let's say that the allele for cystic fibrosis is c. If your Mum has the allele Cc it means she is hetrozygous. If you Dad has the same allele he is also hetrozygous. When they had children, the two small c's could come together to make a child with the alleles cc. (This means that the child has cystic fibrosis and has homozygous reccessive alleles.)

When they had children their alleles could also come together to make CC (homozygous dominant- this means that person doesn't carry an allele for cystic firbrosis and will never get it. This means that if that person had children with another person who has the alleles CC, their child wouldn't get it), or it could make a child with Cc alleles. The child with Cc alleles wouldn't get cystic fibrosis because the allele big C (dominant allele) over powers the allele small c (reccessive- the cystic fibrosis allele). Although this person doesn't have cystic fibrosis their children might because they carry the allele for cystic fibrosis, which is c.