Carney ComplexLast Updated: April 21, 2011 This section has been reviewed and approved by the Cancer.Net Editorial Board, 02/11 Overview
Carney complex is a hereditary condition associated with spotty skin pigmentation, myxomas (benign [noncancerous] connective tissue tumors), and benign or cancerous tumors of the endocrine (hormone producing) glands. Symptoms of Carney complex typically develop when a person is in his or her early 20s. Skin pigmentation and heart myxomas or other heart problems are usually the first signs of the condition. The spotty skin pigmentation is found on lips, inner and outer corners of the eyes, the conjunctiva (membrane lining) of the eye, and around the genital area. Other common features of Carney complex are Cushing’s syndrome (a combination of weight gain, high blood pressure, diabetes, and easy bruising, caused by the overproduction of a specific hormone) and multiple thyroid nodules (tumors). Although people with Carney complex have an increased risk of cancer, most tumors are benign. Carney complex is also called by two other names:
What causes Carney complex? Carney complex is a genetic condition. This means that the cancer risk and other features of Carney complex can be passed from generation to generation in a family through gene(s) mutations (alterations). In particular, researchers have learned more about how the gene called PRKAR1A is associated with Carney complex, through its involvement with regulating the body’s cell signaling with protein kinase A (PKA). Researchers believe that more than 60% of people with Carney complex have a mutation in the PRKAR1A gene and up to 6% may have deletions in this gene. To date, a total of 117 different PRKAR1A mutations have been found. So far, no association between particular mutation type and certain symptoms of Carney complex, such as cancer, has been seen. The search for other genes that might be associated with Carney complex continues. How is Carney complex inherited? Normally, every cell has two copies of each gene: one inherited from the mother and one inherited from the father. Carney complex follows an autosomal dominant inheritance pattern, in which a mutation happens in only one copy of the gene. This means that a parent with a gene mutation may pass along a copy of their normal gene or a copy of the gene with the mutation. Therefore, a child who has a parent with a mutation has a 50% chance of inheriting that mutation. A brother, sister, or parent of a person who has a mutation also has a 50% chance of having the same mutation. How common is Carney complex? Carney complex is very rare. About 500 cases have been reported worldwide. It is estimated that between 60% and 75% of cases of Carney complex run in families. The remaining 25% to 40% of cases appear to be sporadic (occurs by chance) and may be due to a de novo (new) gene mutation. How is Carney complex diagnosed? Carney complex is diagnosed when a person has at least two of the 12 major features listed below. People who have a close family member (parent, sibling, or child) already diagnosed with Carney complex are considered to be affected if they have at least one of the features listed. Major diagnostic features for CNC
Genetic testing for mutations in the PRKAR1A gene is available for people suspected to have Carney complex; if a patient has a PRKAR1A mutation and one of the above tumors or other lesions, then he or she is diagnosed with Carney complex. In addition, other physical symptoms have been seen in people with Carney complex. These physical signs may suggest Carney complex, but they are not considered major diagnostic features. Research is ongoing to learn more about these symptoms and their link, if any, to the condition.
What are the estimated cancer risks associated with Carney complex? The risk of cancer is increased in people who have Carney complex, but the specific risk for cancer is unknown. Types of cancer reported in people with Carney complex include thyroid, colorectal, and pancreatic cancers. Cancer of the testes (a man’s testicles) involving the Sertoli or Leydig cells has also been reported. What are the screening options for Carney complex? There are no specific screening guidelines for Carney complex. Suggested screening includes:
Screening guidelines may change over time as new technologies are developed and more is learned about Carney complex. It is important to talk with your doctor about appropriate screening tests. Learn more about what to expect when having common tests, procedures, and scans. Questions to ask the doctor If you are concerned about your risk of cancer, talk with your doctor. Consider asking the following questions of your doctor:
If you are concerned about your family history and think you or other family members may have Carney complex, consider asking the following questions:
Additional resources What to Expect When You Meet With a Genetic Counselor National Cancer Institute www.cancer.gov American Cancer Society CancerCare To find a genetic counselor in your area, ask your doctor or visit these websites: National Society of Genetic Counselors National Cancer Institute: Cancer Genetics Services Directory |
