常见问题:囊性纤维化的携带者检测
Cystic fibrosis (CF) is one of the most common life threatening genetic diseases, 大约三分之一的人受到影响,300人. CF的严重程度各不相同, 有些孩子一出生就有症状, and others not diagnosed until they are teenagers or adults.
在CF患者中, a defective gene causes the body to produce an abnormally thick, sticky mucus that clogs the lungs and leads to life threatening lung infections. 这些浓稠的分泌物也会阻塞胰腺, preventing digestive enzymes from reaching the intestines to help break down and absorb food.
囊性纤维化不会影响智力. 大多数患有此病的男性都是不育的.
CF treatment has improved dramatically in the past four decades, although there is no cure. 治疗包括抗生素, dietary enzyme supplements and physical therapy to help clear the lungs. A 肺移植 可能是某些患者的一种选择.
In the past, most patients with CF did not reach adulthood. Now most survive into their 30s, with the average life expectancy being about 37 years.
Cystic fibrosis is inherited in an autosomal recessive manner. Our genes come in pairs, with one copy inherited from each parent. Some genes have mutations in them, and do not function properly. A person with one non-functional copy of the gene is a carrier. Carriers for CF have no symptoms, but can pass the non-functioning gene on to their children. An individual must inherit two non-functioning CF genes – one from each parent – to have CF.
If both parents are carriers there is a 1 in 4 (25 percent) chance that both will pass on the non-functioning gene, which would result in a pregnancy affected with cystic fibrosis.
携带者检测可以通过简单的血液检测. There are over 1,000 mutations that have been found to cause CF. Carrier screening can be done for the most common of these, and will identify about 85 to 90 percent of carriers in the Caucasian population. Carrier testing is also available for other ethnic groups, 但检测率和载波频率各不相同.
If no one in your family has CF, your chance of being a carrier depends upon your ancestry:
- 欧洲白种人,德系犹太人——29人中有1人
- 西班牙裔美国人——46人中有1人
- 非裔美国人——61人中有1人
- 亚裔美国人——90分之一
If you have a family history of CF, your risk may be higher regardless of your ancestry.
是的. 如果你做了测试,没有发现CF突变, your chance of being a CF carrier is reduced but not eliminated. Some people are carriers of a rare CF mutation that cannot be detected by routine screening. There is still a small chance that someone with a negative test result could be a carrier and have a child with CF.
如果你是带菌者,对你的健康没有影响. However, there is a chance that you could have a child with CF. Your partner should undergo carrier screening if this has not already been performed.
如果你们中只有一个被发现是携带者, 你的孩子患CF的几率非常低, 虽然没有完全消除. 如果你们都是携带者, 每次怀孕都是1 / 4, or 25 percent chance of being affected with cystic fibrosis.
If both partners are carriers of cystic fibrosis, prenatal testing is available. 绒毛膜绒毛取样 10到14周 羊膜穿刺术 at 16 to 20 weeks can be performed to determine if the fetus has inherited two copies of the cystic fibrosis gene mutation.
If you and your partner are both carriers and you are thinking of becoming pregnant, 还有其他选择. You can meet with a genetic counselor to discuss these issues.
是的. 在你的孩子出院之前, his or her blood sample will be collected on a piece of filter paper with a simple heel stick. Your baby will be tested for several different conditions, including cystic fibrosis.
了解更多关于囊性纤维化的信息, 遗传咨询, 或者安排携带者或产前检查, 请与 产前诊断中心.
加州大学旧金山分校健康 medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.