Carney complexQ87.1

Carney complex is a rare autosomal dominant syndrome with multiple endocrine neoplasms and lentiginosis caused by defects in the PRKAR1A gene in most patients. The PRKAR1A gene copies for the type 1α regulatory subunit of protein kinase A. Inactivating mutations of PRKAR1A result in aberrant cyclic AMP protein kinase A signaling (Kamilaris CDC et al. 2019) .

The PRKAR1A gene is responsible for 2/3 of the cases (Carney syndrome type I). This syndrome is caused by an autosomal dominant mutation of the PRKAR1A gene (also called CNC1 gene, Carney complex type 1 gene) located at gene locus: 17q23-q24. Because most of the identified PRKAR1A mutations are nonsense mutations that result in the mutant protein being undetectable, no genotype-phenotype correlations are generally observed. Cutaneous lesions (lentigines, melanocytic nevi, and myxomas), although minimal in clinical impact, are the most common and occasionally specific findings supporting early diagnosis.

Carney syndrome type 2 involves a mutation of the CNC2 gene (Carney complex type 2 gene; gene locus: 2p16). Further specification has not been made to date.

Skin: Multiple pigmentary disorders, especially lentigines and blue nevi, preferentially in sun-exposed areas. Acral localized cutaneous myxomas. In contrast to Peutz-Jeghers syndrome, the carriage mucosa is not affected.

Extracutaneous manifestations: Cardiac myxomas (75% of cases), pigmented nodular hyperplasia of the NNR with more or less pronounced Cushing's phenotype.

In 40% of women there are mostly asymptomatic bilateral myxoid fibroadenomas of the mammae.

Bilateral testicular tumors (large cell calcifying Sertoli cell tumors and Leydig cell tumors) develop in more than half of men. Clinically, sexual precociousness often impresses.

Less common are growth hormone secreting pituitary adenomas or pituitary somatotropic hyperplasia leading to acromegaly.

There is a tendency for thyroid tumors, including a predisposition to thyroid cancer (Kamilaris CDC et al. 2019).

Cardiac surgery. Early diagnosis is important(acral myxoma with "freckles" in young adulthood) to clarify concomitant symptoms, especially myxomas on the heart, and to treat them if necessary.

Skin symptoms: If necessary, removal of cutaneous myxomas and conspicuous nevi. In case of cosmetically disturbing lentigines, covering, e.g. with Dermacolor.

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