Experts estimate that each one of us is a carrier for at least 5 genetic conditions. Someone who is a “carrier” usually has no symptoms and often has no family history of the disease.
Most often, it is a genetic condition that follows an autosomal recessive inheritance pattern. When both parents carry the same genetic disease, each of their children has a risk of inheriting two mutated genes (one from the father and one from the mother) and will therefore develop the disorder. Examples of autosomal recessive disorders include: cystic fibrosis, spinal muscular atrophy, Tay-Sachs disease and familial Mediterranean fever.
There is another type of inheritance, called X-linked, in which women are carriers, usually without symptoms, and their sons are at risk of developing the disorder. Examples of X-linked disorders include: fragile-X syndrome, hemophilia and Duchenne muscular dystrophy.