Diseases with autosomal recessive inheritance

In the case of autosomal recessive diseases, both copies of the gene must be mutated for the disease to occur. If only one copy is mutated, the person is said to be a carrier. Thus, a carrier does not have the disease, but can pass on one copy of the mutated gene to offspring.

If both parents are carriers of the same autosomal recessive disease, there is a 25% chance that their child will have the disease, a 25% chance that the child will be healthy, and a 50% chance that the child will be a carrier.

The image shows some diseases with this type of inheritance, such as Fanconi anaemia and cystic fibrosis.