What is Carney complex?

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 at the age of 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 and multiple thyroid nodules. Although people with Carney complex have an increased risk of cancer, most tumors are benign.

Carney complex is also known by two other names:

• NAME syndrome – Nevi, Atrial myxoma, Myxoid neurofibromas, and Ephelides (freckles)
  
  
• LAMB syndrome – Lentigines, Atrial Myxoma, and Blue nevi

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. Two genes have been associated with Carney complex. They are called PRKAR1A and CNC2. Researchers believe that about 40% of people with Carney complex have a mutation (alteration) in the PRKAR1A gene. Researchers also believe that other genes may be associated with Carney complex, and studies are ongoing to learn more about this condition.

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. Fewer than 400 cases have been reported worldwide. It is estimated that between 50% and 70% of cases of Carney complex run in families. The remaining 30% to 50% 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 features listed below. People who have a close family member (parent, sibling, or child) with Carney complex are considered to be affected if they have only one of the features listed.

• Spotty skin pigmentation
  
  
• Myxoma
  
  
• Cardiac myxoma
  
  
• Breast myxomatosis
  
  
• Breast ductal adenomas
  
  
• Cushing's syndrome
  
  
• Acromegaly (increased size of hands, feet, and face due to a pituitary tumor)
  
  
• Testicular neoplasms
  
  
• Thyroid neoplasms
  
  
• Melanotic schwannoma
  
  
• Blue nevi
  
  
• Osteochondromyxoma

Genetic testing for mutations in the PRKAR1A gene is available for people suspected to have Carney complex.

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, pancreatic, and testicular cancers. Cancer of the Sertoli-Leydig cells of the testes and liposarcomas (cancer of the fat cells) have also been reported.

What are the screening options for Carney complex?

There are no specific screening guidelines for Carney complex. Suggested screening includes:

• Yearly echocardiogram (EKG), beginning in infancy
  
  
• Regular skin evaluations
  
  
• Yearly blood tests to check serum levels of cortisol, prolactin, and insulin-like growth factor 1 (IGF-1), beginning in adolescence
  
  
• Thyroid examinations
  
  
• General endocrine system screening
  
  
• Testicular examinations for men

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.

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:

• What is my risk of developing cancer?
  
  
• What can I do to reduce my risk of cancer?
  
  
• What are my options for cancer screening?

If you are concerned about your family history and think you or other family members may have Carney complex, consider asking the following questions:

• Does my family history increase my risk of developing cancer?
  
  
• Should I meet with a genetic counselor?
  
  
• Should I consider genetic testing?

Additional resources

Cancer.Net Guide to Thyroid Cancer

Cancer.Net Guide to Colorectal Cancer

Cancer.Net Guide to Pancreatic Cancer

Cancer.Net Guide to Testicular Cancer

What to Expect When You Meet With a Genetic Counselor

National Cancer Institute (NCI)
www.nci.nih.gov

American Cancer Society
www.cancer.org

CancerCare
www.cancercare.org

To find a genetic counselor in your area, ask your doctor or visit these websites:

National Society of Genetic Counselors
www.nsgc.org

National Cancer Institute:
www.cancer.gov/search/geneticsservices