Carney syndrome

Carney Syndrome

Carney syndrome, also known as Carney complex, is a rare genetic disorder characterized by multiple neoplasias, skin pigmentation abnormalities, and endocrine overactivity. It was first described by Dr. J. Aidan Carney in 1985. The syndrome is inherited in an autosomal dominant pattern and is associated with mutations in the PRKAR1A gene.

Clinical Features

Carney syndrome presents with a variety of clinical features, which can vary significantly among affected individuals. The most common manifestations include:

• Myxomas: These are benign tumors that can occur in the heart (cardiac myxomas), skin, and other tissues. Cardiac myxomas are particularly significant due to their potential to cause embolic events and obstructive cardiac symptoms.

• Skin Pigmentation: Patients often exhibit lentigines, which are small, pigmented spots on the skin, and blue nevi, which are blue-colored moles.

• Endocrine Abnormalities: These include Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD), acromegaly due to growth hormone-secreting pituitary adenomas, and thyroid nodules or cancer.

• Schwannomas: These are nerve sheath tumors that can occur in various locations, including the skin and the gastrointestinal tract.

Genetic Basis

Carney syndrome is primarily caused by mutations in the PRKAR1A gene, which encodes the regulatory subunit type 1-alpha of protein kinase A (PKA). This gene is located on chromosome 17q24. The mutations lead to dysregulation of PKA activity, contributing to tumorigenesis and other features of the syndrome.

Diagnosis

The diagnosis of Carney syndrome is based on clinical criteria, genetic testing, and family history. Key diagnostic criteria include the presence of two or more of the following:

• Cardiac myxoma
• Cutaneous myxoma
• Spotty skin pigmentation
• Endocrine tumors or overactivity
• Family history of Carney syndrome

Genetic testing for PRKAR1A mutations can confirm the diagnosis.

Management

Management of Carney syndrome involves regular surveillance for the development of tumors and endocrine abnormalities. Surgical removal of myxomas and other tumors is often necessary. Endocrine disorders are managed according to standard protocols for the specific condition, such as adrenalectomy for Cushing's syndrome.

Prognosis

The prognosis for individuals with Carney syndrome varies depending on the severity and location of the tumors. Cardiac myxomas can be life-threatening if not treated promptly. Regular monitoring and early intervention are crucial to managing the condition effectively.

Also see

• Multiple Endocrine Neoplasia
• Neurofibromatosis
• Peutz-Jeghers Syndrome