If both parents are carriers of recessive genes that can cause a birth defect, there is a one in four chance that each of their children will inherit the disease. The problem with this type of inheritance is that since the parents appear normal, they are not aware that they are both carriers for a particular disorder until they have a child that is effected with this disease. Having a child with a severe genetic disorder is very difficult to deal with especially if you are not prepared and are unaware that you are both carriers. Recessively inherited diseases often are severe and may lead to an early death, two examples are Tay-Sachs disease and cystic fibrosis. Tay-Sachs disease causes severe mental retardation and an early dealt.
Cystic fibrosis is a severe disorder of the lungs and digestive system.