A Novel Missense PRKAR1A Variant Causes Carney Complex.

The Carney complex (CNC) is an autosomal dominant disorder characterized by endocrine and nonendocrine tumors. Loss-of-function variants of protein kinase A regulatory subunit 1 alpha (PRKAR1A) are common causes of CNC. Here, we present the case of a patient with CNC with a novel PRKAR1A missense variant. A 21-year-old woman was diagnosed with CNC secondary to acromegaly and adrenal Cushing syndrome. Genetic analysis revealed a novel missense heterozygous variant of PRKAR1A (c.176A>T). Her relatives, suspected of having CNC, also carried the same variant. RNA analysis revealed that this variant led to nonsense-mediated mRNA decay. In vitro functional analysis of the variant confirmed its role in increasing protein kinase A activity and cyclic adenosine monophosphate levels. This study broadens our understanding of the genetic spectrum of CNC. We suggest that PRKAR1A genetic testing and counseling be recommended for patients with CNC and their families.

Vulvar Cutaneous Myxoma in a Patient With Carney Complex: Avoiding Pitfalls of Myxoid Lesions of the Vulva.

We present the case of a 31-year-old woman who underwent surgical excision for a polypoid, vulvar lesion. Histopathological analysis showed a diffuse myxoid stroma admixed with scant collagen fibrils. Thin-walled and branching blood vessels were prominent, with a mild perivascular lymphocytic infiltrate. Cytologically bland spindle cells with inconspicuous nucleoli were immersed in a loose myxoid stroma. This combination of histopathological features along with multinodularity in the subcutaneous fat raised concern for deep angiomyxoma, a locally destructive neoplasm. Among our differential of myxoid lesions of the vulva, we ultimately favored the diagnosis of vulvar cutaneous myxoma. Upon further investigation, we learned that our patient was indeed known for the Carney complex. We highlight that vulvar cutaneous myxomas arising in the context of the Carney complex pose a significant diagnostic challenge for pathologists and should not be overdiagnosed as aggressive lesions such as deep angiomyxoma or other malignant stromal neoplasms.

Protein kinase A drives paracrine crisis and WNT4-dependent testis tumor in Carney complex.

Large-cell calcifying Sertoli cell tumors (LCCSCTs) are among the most frequent lesions occurring in male Carney complex (CNC) patients. Although they constitute a key diagnostic criterion for this rare multiple neoplasia syndrome resulting from inactivating mutations of the tumor suppressor PRKAR1A, leading to unrepressed PKA activity, LCCSCT pathogenesis and origin remain elusive. Mouse models targeting Prkar1a inactivation in all somatic populations or separately in each cell type were generated to decipher the molecular and paracrine networks involved in the induction of CNC testis lesions. We demonstrate that the Prkar1a mutation was required in both stromal and Sertoli cells for the occurrence of LCCSCTs. Integrative analyses comparing transcriptomic, immunohistological data and phenotype of mutant mouse combinations led to the understanding of human LCCSCT pathogenesis and demonstrated PKA-induced paracrine molecular circuits in which the aberrant WNT4 signal production is a limiting step in shaping intratubular lesions and tumor expansion both in a mouse model and in human CNC testes.

Cardiac myxoma and neural crests: a tense relationship.

In cardiac myxomas, the malignant transformation process, selecting incidental gene mutations and leading to loss of proliferation control, has not a so drastic effects in terms of growth rate of tumor mass, but frequently the particular location of lesion engrosses the high risk for health. For accurate cancer cell profiling, it is important to establish the embryologic origin of malignant cells and their initial commitments, above all, in the sight of therapeutic strategies and solutions. Here, we advance, for cardiac myxoma, the hypothesis of an origin from cardiac neural crest cells and we attempt to support it by an integrated discussion of current knowledge about embryological characteristics of neural crest cells and most recent studies focusing cardiac myxomas. We discuss the relationship between the basic plasticity of cardiac neural crest cells and some typical mutations arising in neoplastic lesions as well as the expression of typical cell markers of neural crests derivatives. Dysfunctions in proliferative and migratory programs, focused in other studies, are evaluated in the context of the topological and histopathological characteristics of cardiac myxomas.

Hormonal and spatial control of SUMOylation in the human and mouse adrenal cortex.

SUMOylation is a highly conserved and dynamic post-translational mechanism primarily affecting nuclear programs for adapting organisms to stressful challenges. Alteration of SUMOylation cycles leads to severe developmental and homeostatic defects and malignancy, but signals coordinating SUMOylation are still unidentified. The adrenal cortex is a zonated endocrine gland that controls body homeostasis and stress response. Here, we show that in human and in mouse adrenals, SUMOylation follows a decreasing centripetal gradient that mirrors cortical differentiation flow and delimits highly and weakly SUMOylated steroidogenic compartments, overlapping glomerulosa, and fasciculata zones. Activation of PKA signaling by acute hormonal treatment, mouse genetic engineering, or in Carney complex results in repression of small ubiquitin-like modifier (SUMO) conjugation in the inner cortex by coordinating expression of SUMO pathway inducers and repressors. Conversely, genetic activation of canonical wingless-related integration site signaling maintains high SUMOylation potential in the outer neoplastic cortex. Thus, SUMOylation is tightly regulated by signaling pathways that orchestrate adrenal zonation and diseases.-Dumontet, T., Sahut-Barnola, I., Dufour, D., Lefrançois-Martinez, A.-M., Berthon, A., Montanier, N., Ragazzon, B., Djari, C., Pointud, J.-C., Roucher-Boulez, F., Batisse-Lignier, M., Tauveron, I., Bertherat, J., Val, P., Martinez, A. Hormonal and spatial control of SUMOylation in the human and mouse adrenal cortex.

Carney Complex.

Carney complex is a rare, autosomal dominant, multiple endocrine neoplasia and lentiginosis syndrome, caused in most patients by defects in the PRKAR1A gene, which encodes the regulatory subunit type 1α of protein kinase A. Inactivating defects of PRKAR1A lead to aberrant cyclic-AMP-protein kinase A signaling. Patients may develop multiple skin abnormalities and a variety of endocrine and non-endocrine tumors. Endocrine manifestations include primary pigmented nodular adrenocortical disease, that may cause Cushing syndrome, growth-hormone secreting pituitary adenoma or pituitary somatotropic hyperplasia which can result in acromegaly, as well as gonadal and thyroid tumors. Non-endocrine tumors associated with Carney complex include myxomas of the heart, breast, and other sites, psamommatous melanotic schwannomas, breast ductal adenomas, osteochondromyxomas, and a predisposition to a number of malignancies from adrenal to pancreatic and liver cancer.

Carney complex review: Genetic features. / Revisión del complejo de Carney: Aspectos genéticos.

Carney complex is a multiple neoplasia syndrome having endocrine and non-endocrine manifestations. Diagnostic criteria include myxoma, lentigines, and primary pigmented nodular adrenocortical disease, amongst other signs/symptoms. In most cases it is an autosomal dominant disease, and diagnosis therefore requires study and follow-up of the family members. Inactivating mutations of the PRKAR1A gene were identified as the main cause of the disease, although since 2015 other disease-related genes, including PRKACA and PRKACB activating mutations, have also been related with Carney complex. This review will address the genetic aspects related to Carney complex.

Growth hormone and risk for cardiac tumors in Carney complex.

Carney complex (CNC) is a multiple neoplasia syndrome that is caused mostly by PRKAR1A mutations. Cardiac myxomas are the leading cause of mortality in CNC patients who, in addition, often develop growth hormone (GH) excess. We studied patients with CNC, who were observed for over a period of 20 years (1995-2015) for the development of both GH excess and cardiac myxomas. GH secretion was evaluated by standard testing; dedicated cardiovascular imaging was used to detect cardiac abnormalities. Four excised cardiac myxomas were tested for the expression of insulin-like growth factor-1 (IGF-1). A total of 99 CNC patients (97 with a PRKAR1A mutation) were included in the study with a mean age of 25.8 ± 16.6 years at presentation. Over an observed mean follow-up of 25.8 years, 60% of patients with GH excess (n = 46) developed a cardiac myxoma compared with only 36% of those without GH excess (n = 54) (P = 0.016). Overall, patients with GH excess were also more likely to have a tumor vs those with normal GH secretion (OR: 2.78, 95% CI: 1.23-6.29; P = 0.014). IGF-1 mRNA and protein were higher in CNC myxomas than in normal heart tissue. We conclude that the development of cardiac myxomas in CNC may be associated with increased GH secretion, in a manner analogous to the association between fibrous dysplasia and GH excess in McCune-Albright syndrome, a condition similar to CNC. We speculate that treatment of GH excess in patients with CNC may reduce the likelihood of cardiac myxoma formation and/or recurrence of this tumor.

Identification of a novel mutation of the PRKAR1A gene in a patient with Carney complex with significant osteoporosis and recurrent fractures.

OBJECTIVE: Carney complex (CNC) is a rare autosomal dominant multiple neoplasia syndrome characterized by the presence of endocrine and non-endocrine tumors. More than 125 different germline mutations of the protein Kinase A type 1-α regulatory subunit (PRKAR1A) gene have been reported. We present a novel PRKAR1A gene germline mutation in a patient with severe osteoporosis and recurrent vertebral fractures. DESIGN: Clinical case report. CASE REPORT: A 53-year-old male with a medical history of surgically removed recurrent cardiac myxomas was evaluated for repeated low-pressure vertebral fractures and severe osteoporosis. Physical examination revealed spotty skin pigmentation of the lower extremities and papules in the nuchal and thoracic region. The presence of hypercortisolism due to micronodular adrenal disease and the history of cardiac myxomas suggested the diagnosis of CNC; the patient underwent detailed imaging investigation and genetic testing. METHODS: Standard imaging and clinical testing; DNA was sequenced by the Sanger method. RESULTS: Sequence analysis from peripheral lymphocytes DNA revealed a novel heterozygous point mutation at codon 172 of exon 2 (c.172G>T) of the PRKAR1A gene, resulting in early termination of the PRKAR1A transcript [p.Glu58Ter (E58X)]. CONCLUSION: We report a novel point mutation of the PRKAR1A gene in a patient with CNC who presented with significant osteoporosis and fractures. Low bone mineral density along with recurrent myxomas should point to the diagnosis of CNC.

A Novel Inherited Mutation in PRKAR1A Abrogates PreRNA Splicing in a Carney Complex Family.

BACKGROUND: Carney complex (CNC) is an autosomal dominant inherited disease, characterized by spotty skin pigmentation, cardiac and cutaneous myxomas, and endocrine overactivity. We report on a Chinese CNC family with a novel mutation in the protein kinase A regulatory subunit 1 (PRKAR1A) gene. METHODS: Target-exome sequencing was performed to identify the mutation of PRKAR1A in 2 members of the CNC family. RESULTS: The proband was a young man with typical CNC, including pigmentation, cutaneous myxomas, cardiac myxoma, Sertoli cell tumour of his left testis, and multiple hypoechoic thyroid nodules. His mother also had CNC with skin pigmentation, cutaneous myxomas, and a cardiac myxoma. Target-exome capture analysis revealed that the proband and the mother carried a novel heterozygous mutation in the exon 6 splicing donor site of PRKAR1A. Sequencing analysis of myxoma messenger RNA revealed that the mutation abrogated exon 6 preRNA splicing, leading to a frameshift starting at Valine 185 and premature translation termination in intron 6. The truncated enzyme lacks the functional cyclic adenosine monophosphate (cAMP) binding domain at the C-terminus, causing PRKAR1A haploinsufficiency. CONCLUSIONS: In this study we report on a novel splicing mutation in the PRKAR1A gene that adds to the genetic heterogeneity of CNC.

Conjunctival myxoma: a synopsis of a rare ocular tumor.

Conjunctival myxoma is an exceptionally rare, slow-growing, benign neoplasm of primitive mesenchyme origin. Forty-one cases of conjunctival myxoma from a literature review, including the authors' case, are listed. The usual clinical history is a painless mass appearing during months to years. Grossly, the tumor is a well-circumscribed, cystlike, gelatinous, yellow-to-pink, translucent-to-solid mass. Microscopically, the hypocellular tumor contains stellate- and spindle-shaped cells in a mucoid stroma with abundant hyaluronic acid mucopolysaccharides. Vimentin and α-smooth muscle actin highlight the spindle and stellate cells. S100 protein and desmin are negative for the tumor cells. Treatment is complete surgical excision, with no recurrence reported in the follow-up period. Notably, conjunctival myxoma may be associated with Carney complex, an autosomal-dominant disorder associated with skin pigmentation, endocrine abnormalities, and myxoma of the heart and eye. Physicians should appreciate this unique ocular tumor because of its potential association with Carney complex.

Primary pigmented nodular adrenocortical disease: the original 4 cases revisited after 30 years for follow-up, new investigations, and molecular genetic findings.

The original 4 patients with Cushing syndrome who underwent bilateral adrenalectomy for primary pigmented nodular adrenocortical disease were followed up for an average of 31 years to determine whether they or any of their primary relatives had developed Carney complex or its components. None had. Three of the patients were alive and well; the fourth had died of an unrelated condition. All the adrenal glands contained multiple small, black or brown cortical nodules, up to 4 mm in diameter. The extracapsular extension of the micronodules was limited to the immediate pericapsular adipose tissue and was not considered evidence of low-grade malignancy. Immunocytochemically, the nodules were positive for synaptophysin, inhibin-A, and melan A and negative for vimentin and CD56. Ki-67 antibody stained the cytoplasm of cells in the micronodules but not that of the atrophic cortical cells. The 4 patients had the PRKAR1A deletion that has been associated with the isolated form of primary pigmented nodular adrenocortical disease.

Inactivation of the Carney complex gene 1 (PRKAR1A) alters spatiotemporal regulation of cAMP and cAMP-dependent protein kinase: a study using genetically encoded FRET-based reporters.

Carney complex (CNC) is a hereditary disease associating cardiac myxoma, spotty skin pigmentation and endocrine overactivity. CNC is caused by inactivating mutations in the PRKAR1A gene encoding PKA type I alpha regulatory subunit (RIα). Although PKA activity is enhanced in CNC, the mechanisms linking PKA dysregulation to endocrine tumorigenesis are poorly understood. In this study, we used Förster resonance energy transfer (FRET)-based sensors for cAMP and PKA activity to define the role of RIα in the spatiotemporal organization of the cAMP/PKA pathway. RIα knockdown in HEK293 cells increased basal as well as forskolin or prostaglandin E1 (PGE1)-stimulated total cellular PKA activity as reported by western blots of endogenous PKA targets and the FRET-based global PKA activity reporter, AKAR3. Using variants of AKAR3 targeted to subcellular compartments, we identified similar increases in the response to PGE1 in the cytoplasm and at the outer mitochondrial membrane. In contrast, at the plasma membrane, the response to PGE1 was decreased along with an increase in basal FRET ratio. These results were confirmed by western blot analysis of basal and PGE1-induced phosphorylation of membrane-associated vasodilator-stimulated phosphoprotein. Similar differences were observed between the cytoplasm and the plasma membrane in human adrenal cells carrying a RIα inactivating mutation. RIα inactivation also increased cAMP in the cytoplasm, at the outer mitochondrial membrane and at the plasma membrane, as reported by targeted versions of the cAMP indicator Epac1-camps. These results show that RIα inactivation leads to multiple, compartment-specific alterations of the cAMP/PKA pathway revealing new aspects of signaling dysregulation in tumorigenesis.

PKA RIα homodimer structure reveals an intermolecular interface with implications for cooperative cAMP binding and Carney complex disease.

The regulatory (R) subunit is the cAMP receptor of protein kinase A. Following cAMP binding, the inactive PKA holoenzyme complex separates into two active catalytic (C) subunits and a cAMP-bound R dimer. Thus far, only monomeric R structures have been solved, which fell short in explaining differences of cAMP binding for the full-length protein as compared to the truncated R subunits. Here we solved a full-length R-dimer structure that reflects the biologically relevant conformation, and this structure agrees well with small angle X-ray scattering. An isoform-specific interface is revealed between the protomers. This interface acts as an intermolecular sensor for cAMP and explains the cooperative character of cAMP binding to the RIα dimer. Mutagenesis of residues on this interface not only leads to structural and biochemical changes, but is also linked to Carney complex disease.

Systematic screening for PRKAR1A gene rearrangement in Carney complex: identification and functional characterization of a new in-frame deletion.

BACKGROUND: Point mutations of the PRKAR1A gene are a genetic cause of Carney complex (CNC) and primary pigmented nodular adrenocortical disease (PPNAD), but in 30% of the patients no mutation is detected. OBJECTIVE: Set up a routine-based technique for systematic detection of large deletions or duplications of this gene and functionally characterize these mutations. METHODS: Multiplex ligation-dependent probe amplification (MLPA) of the 12 exons of the PRKAR1A gene was validated and used to detect large rearrangements in 13 typical CNC and 39 confirmed or putative PPNAD without any mutations of the gene. An in-frame deletion was characterized by western blot and bioluminescence resonant energy transfer technique for its interaction with the catalytic subunit. RESULTS: MLPA allowed identification of exons 3-6 deletion in three patients of a family with typical CNC. The truncated protein is expressed, but rapidly degraded, and does not interact with the protein kinase A catalytic subunit. CONCLUSIONS: MLPA is a powerful technique that may be used following the lack of mutations detected by direct sequencing in patients with bona fide CNC or PPNAD. We report here one such new deletion, as an example. However, these gene defects are not a frequent cause of CNC or PPNAD.

Pituitary adenoma with mucin cells in a man with an unusual presentation of Carney complex.

We describe a 44-year-old man with infertility, acromegaly, and hypergonadotropic hypogonadism. Clinical examination of the patient revealed hyperpigmented macules on the lips, buccal mucosa, and face which were histologically confirmed as cutaneous myxomas and blue nevi. Ultrasound revealed testicular calcifications and multiple hypoechoic thyroid nodules. MR imaging showed a pituitary microadenoma and resection revealed it to be a growth hormone and prolactin-secreting adenoma with the unusual finding of admixed individual mucin-producing cells. We discuss mucin cells in pituitary adenoma, an unreported pathologic finding in a patient with Carney complex.

Adrenal cortical adenoma: the fourth component of the Carney triad and an association with subclinical Cushing syndrome.

The Carney triad is the combination of gastric stromal sarcoma, pulmonary chondroma, and extra-adrenal paraganglioma. Herein, we describe the clinical, imaging, pathologic, and follow-up findings from 14 patients for a fourth component of the syndrome, adrenal adenoma. The adrenal neoplasm was asymptomatic and usually a late finding. Results of adrenocortical function tests were normal. Computed tomography revealed low-density adrenal masses that were consistent with adenomas. Bilateral lesions were present in 4 patients. In 13 of the 14 patients who underwent surgery, resected adrenal glands and biopsy specimens featured 1 or more circumscribed, yellow tumors, up to 3.5 cm in diameter, composed of well-differentiated polygonal cells with clear vacuolated cytoplasm and a smaller component of eosinophilic cells. The extratumoral cortex had combinations of normal histologic features, discrete clear cell micronodules, zonal clear cell hypertrophy, and marked atrophy. The lesion in the 14th patient was different, grossly and microscopically resembling the usual sporadic cortisol-secreting adenoma. After the tumor was excised, the patient required glucocorticoid support. None of the tumors recurred or metastasized. Fourteen additional patients had unilateral or bilateral adrenal tumors consistent with adenomas detected by imaging studies.

Epithelioid and fusiform blue nevus of chronically sun-damaged skin, an entity distinct from the epithelioid blue nevus of the Carney complex.

Epithelioid blue nevus (EBN) was first described in patients with Carney complex (CNC) and subsequently shown to also occur sporadically. Over 50% of patients with CNC harbor mutations in the gene PRKAR1A, which codes for protein kinase A regulatory subunit 1α (R1α) involved in the signaling pathway regulating melanogenesis and melanocytic proliferation. Immunohistochemical expression of R1α has been shown to be absent in the majority of pigmented epithelioid melanocytomas and all CNC-associated EBNs but present in melanomas and other melanocytic nevi. We have observed several examples of EBN occurring in chronically sun-damaged (CSD) skin with a predominance of epithelioid morphology but also containing a component of fusiform and conventional blue nevus cells, which we have termed epithelioid and fusiform blue nevus of CSD skin. Several of these cases demonstrated notable pleomorphism and nuclear atypia with rare mitotic activity raising concern for the possibility of melanoma; however, the clinical outcomes, detailed histologic review, and molecular results were most consistent with a benign melanocytic neoplasm. We report our clinical, histopathologic, immunohistochemistry, and fluorescence in situ hybridization experience with this distinct entity of epithelioid and fusiform blue nevus and demonstrate that it is a unique subtype of blue nevus occurring on CSD skin with a higher frequency of an associated conventional blue nevus component compared with EBN and without association with CNC or loss of R1α expression typically found in pigmented epithelioid melanocytoma and CNC-associated EBN. We also postulate that the epithelioid pattern may represent a subclone of the conventional blue nevus component induced by chronic UV damage.

In vitro studies of novel PRKAR1A mutants that extend the predicted RIα protein sequence into the 3'-untranslated open reading frame: proteasomal degradation leads to RIα haploinsufficiency and Carney complex.

BACKGROUND: Carney complex (CNC) is a multiple endocrine neoplasia syndrome due to inactivating mutations in the PRKAR1A gene that codes for type Iα regulatory (RIα) subunit of protein kinase A. Most PRKAR1A mutations are subject to nonsense mRNA decay (NMD) and, thus, lead to haploinsufficiency. METHODS AND SETTING: Patient phenotyping for CNC features and DNA, RNA, protein, and transfection studies were carried out at a research center. RESULTS: We describe in unrelated kindreds with CNC four naturally occurring PRKAR1A mutations (1055del4, 1067del4ins5, 1076delTTins13, and 1142del4) that are predicted to escape NMD because they are located in the last coding exon of the gene. The phenotype of CNC was not different from that in other patients with the condition, although the number of patients was small. Each of the mutations caused a frameshift that led to a new stop codon into the 3' untranslated open reading frame, predicting an elongated protein that, however, was absent in patient-derived cells. After site-directed mutagenesis, in vitro transcription, and cell-free translation experiments, the expected size mutant proteins were present. However, when the mutant constructs were transfected in adrenal (NCI-295), testicular (N-TERA), and embryonic (HEK293) cells and despite the presence of the mutant mRNA, Western blot analysis indicated that there were no longer proteins. The subsequent application of proteasome inhibitors to cells transfected with the mutant constructs led to the detection of the aberrant proteins, although a compound that affects protein folding had no effect. The wild-type protein was also decreased in both patient-derived cells and/or tissues as well as in the in vitro systems used in this study. CONCLUSIONS: This was the first demonstration of proteasomal degradation of RIα protein variants leading to PRKAR1A haploinsufficiency and CNC, adding protein surveillance to NMD in the cellular mechanisms overseeing RIα synthesis. In agreement with the molecular data, CNC patients bearing PRKAR1A defects that extend the open reading frame did not have a different phenotype, although this has to be confirmed in a larger number of patients.