“Woe is the child kissed on the brow who tastes salty, for he is cursed and soon must die.” A warning from the Middle Ages about “bewitched” or “hexed” children who tasted salty when kissed and died soon after birth. The disease described is cystic fibrosis, so named in the 1930s because it leaves a fibrous scar on affected organs. Cystic fibrosis is one of the most common life threatening genetic diseases, affecting more than 70,000 people around the world. However, unlike in the Middle Ages, today most people with cystic fibrosis live well into their 30s, due to breakthroughs in treatment and management of the disease.
Cystic fibrosis (CF) is an inherited disease, which involves the production of extremely salty sweat and the over-production of sticky mucus in the lungs and the digestive system. It is caused by defects in a single gene called CFTR. The disease is recessive, meaning you need to inherit two defective copies of the CFTR gene to develop the disease. The CFTR gene gives instructions to make a channel that controls the movement of salt in the body. Genetic changes in this gene increase the body’s production of mucus, sweat and digestive fluid. Mucus occurs naturally in the body and covers the lining of organs and tissue like the lungs and the digestive system, lubricating and protecting them from damage. Normal mucus is thin and slippery, but the mucus of people with CF is thick and sticky, and can clog the affected organs. People with CF also make very salty sweat and abnormally thick digestive fluids.
In the early 1960s, the life expectancy of a CF patient was just 10 years. This was extended to 18 in the 1980s and CF patients may live well into their fourth decade today. However, life is not without its challenges. Major symptoms of CF include frequent lung infections (including pneumonia and bronchitis) and serious digestive problems. Patients have their ups when all systems function normally, but can experience the downs of the disease just a short while later. When things take a turn for the worse, immediate hospitalization is needed.
There is no cure for CF. But many medical discoveries have been made already, such as antibiotics like Cayston to prevent lung infections and drugs like pulmozyme to increase mucus breakdown. The FDA approval for the ‘fast track’ clinical trials of a new the CF drug, N9115, and the latest finding of fusicoccin-A, a naturally occurring substance that has the potential to be developed into a drug to cure CF, most definitely offers renewed hope for the future. CF patients can now often hold full-time jobs, run marathons, become professionals and even start their own families.
In the past five to six decades, cystic fibrosis has evolved from being a lethal-pediatric disease to a chronic medical condition. This brings with it new demands on the healthcare system, because the type and severity of symptoms vary from patient to patient, requiring personalized care. With many CF patients surviving into their adulthood and having children who may be genetic carriers of the disease, genetic testing has become an important part of their family planning. If two CF carriers have children, there is a 1 in 4 chance that the child will have the disease. If a CF patient has children with a carrier, there is a 50% chance the child will inherit the disease and a 50% chance that they will be a genetic carrier.
Today, genetic testing allows couples wishing to have children to find out if they are carriers of this disease and predict their risk of having an affected child, allowing them a better understanding of risks when planning their family.
