In Europe, the most common autosomal recessive disease is cystic fibrosis. The disease causes destruction of the lung structure and reduced physical resilience due to inflammation of the airways. The prognosis for those affected has improved considerably due to medical advances, including lung transplantation. Spinal muscular atrophy is another common autosomal recessive disease. It is characterised by progressive degeneration of nerve cells in the spinal cord. Despite advances in treatment, the prognosis for many patients remains poor.