Carney complex
Encyclopedia
Carney complex, also known as LAMB syndrome and NAME syndrome is an autosomal dominant condition comprising myxoma
s of the heart and skin, hyperpigmentation of the skin (lentiginosis
), and endocrine overactivity It is distinct from Carney's triad
. Approximately 7% of all cardiac myxomas are associated with Carney complex.
gene on chromosome 17q23-q24,
which may function as a tumor-suppressor gene. The encoded protein is a type 1A regulatory subunit of protein kinase A. Inactivating germline mutations of this gene are found in 70% of people with Carney complex.
Less commonly, the molecular pathogenesis of Carney complex is a variety of genetic changes at chromosome 2p16.
Both types of Carney complex are autosomal dominant. Despite dissimilar genetics, there appears to be no phenotypic
difference between PRKAR1A and chromosome 2p16 mutations.
, and oral mucosa. Cardiac myxomas may lead to embolic strokes
and heart failure and may present with fever, joint pain, shortness of breath, diastolic rumble, and tumor plop. Myxomas may also occur outside the heart, usually in the skin and breast. Endocrine tumors may manifest as disorders such as Cushing syndrome. The most common endocrine gland manifestation is an ACTH-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD).
The LAMB
acronym
refers to lentigines, atrial myxoma
s, and blue nevi
. NAME refers to nevi
, atrial myxoma, myxoid neurofibromas, and ephelides.
Although J. Aiden Carney also described Carney's triad
it is entirely different.
Myxoma
A myxoma is a tumor of primitive connective tissue. It is the most common primary tumor of the heart in adults, but can also occur in other locations....
s of the heart and skin, hyperpigmentation of the skin (lentiginosis
Lentiginosis
Lentiginosis refers to the presence of lentigines in large numbers or in a distinctive configuration. These are spotted areas created by accumulation on the skin due to sun exposure. Due to a high irregularity any distinction from randomness defines lentiginosis...
), and endocrine overactivity It is distinct from Carney's triad
Carney's triad
Carney Triad describes the coexistence of several neoplasms, mainly in young women, including: gastric epithelioid leiomyosarcoma , pulmonary chondroma, and extra-adrenal paraganglioma.Recent advances in molecular biology have demonstrated that the so-called gastric epithelioid leiomyosarcomas...
. Approximately 7% of all cardiac myxomas are associated with Carney complex.
Pathophysiology
Carney complex is most commonly caused by mutations in the PRKAR1APRKAR1A
cAMP-dependent protein kinase type I-alpha regulatory subunit is an enzyme that in humans is encoded by the PRKAR1A gene.- Function :cAMP is a signaling molecule important for a variety of cellular functions. cAMP exerts its effects by activating the cAMP-dependent protein kinase A , which...
gene on chromosome 17q23-q24,
which may function as a tumor-suppressor gene. The encoded protein is a type 1A regulatory subunit of protein kinase A. Inactivating germline mutations of this gene are found in 70% of people with Carney complex.
Less commonly, the molecular pathogenesis of Carney complex is a variety of genetic changes at chromosome 2p16.
Both types of Carney complex are autosomal dominant. Despite dissimilar genetics, there appears to be no phenotypic
Phenotype
A phenotype is an organism's observable characteristics or traits: such as its morphology, development, biochemical or physiological properties, behavior, and products of behavior...
difference between PRKAR1A and chromosome 2p16 mutations.
Clinical Features
The spotty skin pigmentation and lentigines occur most commonly on the face, especially on the lips, eyelids, conjunctivaConjunctiva
The conjunctiva covers the sclera and lines the inside of the eyelids. It is composed of rare stratified columnar epithelium.-Function:...
, and oral mucosa. Cardiac myxomas may lead to embolic strokes
Embolism
In medicine, an embolism is the event of lodging of an embolus into a narrow capillary vessel of an arterial bed which causes a blockage in a distant part of the body.Embolization is...
and heart failure and may present with fever, joint pain, shortness of breath, diastolic rumble, and tumor plop. Myxomas may also occur outside the heart, usually in the skin and breast. Endocrine tumors may manifest as disorders such as Cushing syndrome. The most common endocrine gland manifestation is an ACTH-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD).
The LAMB
acronym
Acronym and initialism
Acronyms and initialisms are abbreviations formed from the initial components in a phrase or a word. These components may be individual letters or parts of words . There is no universal agreement on the precise definition of the various terms , nor on written usage...
refers to lentigines, atrial myxoma
Myxoma
A myxoma is a tumor of primitive connective tissue. It is the most common primary tumor of the heart in adults, but can also occur in other locations....
s, and blue nevi
Blue nevus
Blue nevus is a type of melanocytic nevus.It is usually described as non-cancerous, but can be malignant.- Types :Blue nevi may be divided into the following types:...
. NAME refers to nevi
Nevus
Nevus is the medical term for sharply-circumscribed and chronic lesions of the skin. These lesions are commonly named birthmarks and moles. Nevi are benign by definition...
, atrial myxoma, myxoid neurofibromas, and ephelides.
Although J. Aiden Carney also described Carney's triad
Carney's triad
Carney Triad describes the coexistence of several neoplasms, mainly in young women, including: gastric epithelioid leiomyosarcoma , pulmonary chondroma, and extra-adrenal paraganglioma.Recent advances in molecular biology have demonstrated that the so-called gastric epithelioid leiomyosarcomas...
it is entirely different.