NAME syndrome, LAMB syndrome,
Adrenocortical nodular dysplasia,
Carney myxoma-endocrine complex Ca
Monday, 01 August 2005
Last Updated Monday, 01 August 2005
What
Carney complex is a rare, inherited,
genetic disorder that is part of the group of diseases called the lentiginoses. This condition is characterized by multiple myxomas (type of
tumor) involving the skin, heart, nerves, and endocrine organs, as well as pigmented spots on the skin and mucous membranes.
Who
Children with this condition present most frequently within the first 2-3 years of life, adults will most frequently present in their second or third decade. Those with a family history of Carney complex are younger at presentation. Males and females are equally affected and there is no known racial preference.
Signs and Symptoms
Children with Carney complex may exhibit some or all of the following:
- pigmented lentigines (freckles) and dark nevi (moles) on the neck, trunk, and face, including the lips and eyes (eyelids, conjunctivae, sclerae)
- multiple tumors: both endocrine (located in endocrine organs such as the testes, ovaries, adrenals, pituitary, thyroid) and non-endocrine (located in the skin, breasts, heart, nerves). Endocrine tumors cause increased secretion of hormones that leads to a variety of symptoms.
These tumors are considered benign since they generally do not spread throughout the body as a cancer would, however, they can cause serious problems. For example, tumors in the heart (a very common location with Carney complex) can obstruct the valves and compromise normal blood flow. Most concerning are the emboli (small blood clots) that can form from non-circulating blood. These clots travel to small blood vessels in the brain and block them, resulting in stroke. Tumors of the adrenal glands (another common location) predispose children to Cushing’s syndrome (characterized by increased fat tissue in the face, neck, and trunk, emotional instability, increased blood pressure, osteoporosis, muscle weakness, easy bruising, and excessive hair growth). While most Carney complex associated masses are benign, those in the thyroid gland and nervous system can become malignant and behave like a true cancer.
Possible Causes
Currently, two genetic alterations have been identified on two separate chromosomes. The
mutation on
chromosome 17 is referred to as Carney complex type I (CNC1). The one on
chromosome 2 is referred to as Carney complex type II. Both are inherited in an
autosomal dominant fashion, meaning that at least one parent carries the
gene alteration and is affected. CNC1 involves the
tumor suppressor
gene PRKAR1A. This
gene codes for the type 1-alpha regulatory subunit which is part of the
enzyme protein kinase A (PKA). PKA can be turned on or off depending on the needs of the body. The regulatory subunit is necessary to keep PKA turned off. When it is turned on, PKA promotes cell proliferation. The
mutation inactivates the regulatory subunit and the PKA always remains on. Therefore, the current theory is that the
mutation results in a hyperactive PKA that promotes cell proliferation and causes the signs and symptoms of Carney complex.
Diagnosis
Making the diagnosis involves recognition of the characteristic skin findings and imaging by
echocardiography, CT (computed tomography) and/or MRI (magnetic resonance imaging) scan to look for tumors in the internal organs. Blood tests assessing blood counts, thyroid function, adrenal gland function, and evidence for defined genetic alterations are often performed. For myxomas in the heart, an electrocardiogram (EKG) and echocardiogram are usually performed to assess the electrical activity of the heart and function respectively.
Treatment
Unfortunately there is no cure for Carney complex. The goal of therapy is to treat the child symptomatically. The skin findings tend to fade after the fourth decade of life while the myxomas can be surgically removed, depending on their location. There is a higher risk that the
tumor will grow back after surgical removal for those with Carney complex.
Prognosis
Although the disease will decrease life span, this will depend on the severity of the disease in a particular patient and the quality of follow-up care. The common cause of death (57%) is related to heart complications. Other causes include post-operative complications and the progression of
cancer. Current data suggests that there is some improvement in survival if the disease is detected and managed before symptoms appear.
Connect with other parents
In the spirit of community and support, Madisons Foundation offers the unique service of connecting parents of children with rare diseases. If you would like to be connected to other parents of children with this disease,
please fill out this brief form.
Weblinks
Cushing’s Help and Support
This website is for those with Cushing’s disease but they also have a message board for those who have Carney complex.
Gene Reviews
This link provides an informational page on the Carney complex. It focuses on the genetics of Carney complex, but does provide a concise summary of the disease. At the end of the page it provides links to national organizations.
EMedicine
Good article on heart myxomas.
American Heart Association
Everything you need to know about heart disease.
Pituitary Disorders
Support website that educates patients and families.
American cancer Society
www.cancer.org
Provides regional support information.
Google Search for Carney Complex
References and Sources
www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=160980
www.erc.endocrinology-journals.org/cgi/reprint/11/2/265
www.emedicine.com/med/topic2941.htm
www.infobiogen.fr/services/chromcancer/Kprones/CarneyComplexID10080.html
www.online.statref.com/document.aspx?fxid=21&docid=653
Stratakis CA, Matyakhina L, Courkoutsakis N, Patronas N, Voutetakis A, Stergiopoulos S, Bossis I, Carney JA. Pathology and molecular genetics of the pituitary gland in patients with the 'complex of spotty skin pigmentation, myxomas, endocrine overactivity and schwannomas' (Carney complex). Front Horm Res. 2004;32:253-64