Cystic fibrosis is an inherited disease that affects the glands that make mucus and sweat. Children may be born with cystic fibrosis if each parent carries one faulty gene for the disease. Someone with one normal CF gene and one faulty CF gene is known as a cystic fibrosis carrier. You can be a carrier and not have the disease yourself.
Many women find out they are carriers when they become, or are trying to become, pregnant. If their partner is also a carrier, their child may be born with the disease.
If you and your partner are both carriers, you will likely want to understand how likely it is that your child will be born with cystic fibrosis. When two CF carriers have a baby, there is a 25 percent chance that their baby will be born with the disease and a 50 percent chance that their baby will be a carrier of a CF gene mutation, but not have the disease themselves. One in four children will neither be carriers nor have the disease, therefore breaking the chain of heredity.
Many carrier couples decide to undergo a genetic screening test on their embryos, called preimplantation genetic diagnosis (PGD). This test is done prior to pregnancy on embryos acquired through in vitro fertilization (IVF). In PGD, one or two cells are extracted from each embryo and analyzed to determine if the baby will:
- have cystic fibrosis
- be a carrier of the disease
- not have the defective gene at all
The removal of cells does not adversely affect the embryos. Once you know this information about your embryos, you can decide which to have implanted in your uterus in the hopes that a pregnancy will occur.
Women who are carriers of CF do not experience infertility issues because of it. Some men who are carriers have a specific type of infertility. This infertility is caused by a missing duct, called the vas deferens, which transports sperm from the testicles into the penis. Men with this diagnosis have the option of having their sperm recovered surgically. The sperm can then be used to implant their partner through a treatment called intracytoplasmic sperm injection (ICSI).
In ICSI, a single sperm is injected into an egg. If fertilization occurs, the embryo is implanted into the woman’s uterus, through in vitro fertilization. Since not all men who are carriers of CF have infertility issues, it is important that both partners get tested for the defective gene.
Even if both of you are carriers, you can have healthy children.
Many CF carriers are asymptomatic, meaning they have no symptoms. Approximately one in 31 Americans is a symptomless carrier of a defective CF gene. Other carriers experience symptoms, which are usually mild. Symptoms include:
- respiratory problems, such as bronchitis and sinusitis
Cystic fibrosis carriers are found in every ethnic group. Following are estimates of the CF gene mutation carriers in the United States by ethnicity:
- Caucasians: one in 29
- Hispanics: one in 46
- African-Americans: one in 65
- Asian-Americans: one in 90
Regardless of your ethnicity or if you have a family history of cystic fibrosis, you should get tested.
There’s no cure for cystic fibrosis, but lifestyle choices, treatments, and medications can help people with CF live full lives, despite the challenges they face.
Cystic fibrosis primarily affects the respiratory system and digestive tract. Symptoms can range in severity and change over time. This makes the need for proactive treatment and monitoring from medical specialists especially important. It’s crucial to keep immunizations up-to-date and to maintain a smoke-free environment.
Treatment typically focuses on:
- maintaining adequate nutrition
- preventing or treating intestinal blockages
- eliminating mucus from the lungs
- preventing infection
Doctors often prescribe medications to achieve these treatment goals, including:
- antibiotics to prevent and treat infection, primarily in the lungs
- oral pancreatic enzymes to aid in digestion
- mucus-thinning drugs to support loosening and removal of mucus from the lungs through coughing
Other common treatments include bronchodilators, which help keep airways open, and physical therapy for the chest. Feeding tubes are sometimes used overnight to help assure adequate calorie consumption.
People with severe symptoms often benefit from surgical procedures, such as nasal polyp removal, bowel blockage surgery, or lung transplant.
Treatments for CF continue to improve and with them so does the quality and length of life for those who have it.
If you’re hoping to be a parent and find out you’re a carrier, it’s important to remember that you have options and control over the situation.
The American Congress of Obstetricians and Gynecologists (ACOG) recommends offering carrier screening for all women and men who wish to become parents. Carrier screening is a simple procedure. You will need to provide either a blood or saliva sample, which is acquired via a mouth swab. The sample will be sent off to a lab for analysis and provide information about your genetic material (DNA) and will determine if you carry a mutation of the CF gene.