Recurrent left atrial myxoma in Carney complex: A case report of a familial pedigree

Association between subclinical hyperthyroidism and a PRKAR1A gene variant in Carney complex patients: A case report and systematic review

BACKGROUND AND OBJECTIVES

It is currently controversial whether subclinical hyperthyroidism is associated with PRKAR1A gene variants. We describe a man with subclinical hyperthyroidism and a PRKAR1A gene variant who was diagnosed with Carney complex (CNC), and we performed a systematic review of published studies to assess the association between PRKAR1A gene variants and the risk of subclinical hyperthyroidism.

DESIGN AND METHODS

The PubMed, EMBASE, OVID, Science Direct, and gray literature electronic databases were searched for articles published from January 2002 to May 2021 using predefined keywords and inclusion and exclusion criteria. Data on thyroid function from selected studies were extracted and analyzed.

RESULTS

We identified a CNC patient with a subclinical hyperthyroidism phenotype combined with multiple components and genetic sequenced data. In a subsequent systematic review, twenty selected studies (14 case studies and 6 series studies) enrolling 23 individuals were included in the final analysis. The patient's thyroid function data were qualitative in 11 cases and quantitative in 12 cases. The prevalence of subclinical hyperthyroidism in the CNC patients with a PRKAR1A gene variant, including our patient, was markedly higher than that in the normal population (12.5% vs. 2%).

CONCLUSIONS

The findings of this systematic review provide helpful evidence that PRKAR1A gene variants and subclinical hyperthyroidism are related and suggest that subclinical hyperthyroidism may be a neglected phenotype of PRKAR1A gene variants and a novel component of CNC patients.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42021197655.

Gαs-Protein Kinase A (PKA) Pathway Signalopathies: The Emerging Genetic Landscape and Therapeutic Potential of Human Diseases Driven by Aberrant Gαs-PKA Signaling

Many of the fundamental concepts of signal transduction and kinase activity are attributed to the discovery and crystallization of cAMP-dependent protein kinase, or protein kinase A. PKA is one of the best-studied kinases in human biology, with emphasis in biochemistry and biophysics, all the way to metabolism, hormone action, and gene expression regulation. It is surprising, however, that our understanding of PKA's role in disease is largely underappreciated. Although genetic mutations in the PKA holoenzyme are known to cause diseases such as Carney complex, Cushing syndrome, and acrodysostosis, the story largely stops there. With the recent explosion of genomic medicine, we can finally appreciate the broader role of the Gαs-PKA pathway in disease, with contributions from aberrant functioning G proteins and G protein-coupled receptors, as well as multiple alterations in other pathway components and negative regulators. Together, these represent a broad family of diseases we term the Gαs-PKA pathway signalopathies. The Gαs-PKA pathway signalopathies encompass diseases caused by germline, postzygotic, and somatic mutations in the Gαs-PKA pathway, with largely endocrine and neoplastic phenotypes. Here, we present a signaling-centric review of Gαs-PKA-driven pathophysiology and integrate computational and structural analysis to identify mutational themes commonly exploited by the Gαs-PKA pathway signalopathies. Major mutational themes include hotspot activating mutations in Gαs, encoded by GNAS, and mutations that destabilize the PKA holoenzyme. With this review, we hope to incite further study and ultimately the development of new therapeutic strategies in the treatment of a wide range of human diseases. SIGNIFICANCE STATEMENT: Little recognition is given to the causative role of Gαs-PKA pathway dysregulation in disease, with effects ranging from infectious disease, endocrine syndromes, and many cancers, yet these disparate diseases can all be understood by common genetic themes and biochemical signaling connections. By highlighting these common pathogenic mechanisms and bridging multiple disciplines, important progress can be made toward therapeutic advances in treating Gαs-PKA pathway-driven disease.

Identification of a PRKAR1A mutation (c.491_492delTG) in familial cardiac myxoma: A case report

RATIONALE

Cardiac myxoma is the most common cardiac neoplasm. Currently, there are not many reports on familial cardiac myxoma. Herein, we reported 2 first-degree relatives with left atrial myxoma.

PATIENT CONCERNS

A 20-year-old female was admitted in our hospital for lapsing into a coma for 24 hours, and was diagnosed with recurrent left atrial cardiac myxoma. The patient's father also had a history of cardiac myxoma.

DIAGNOSIS

The patient was diagnosed with left atrial myxoma using transthoracic echocardiography (TTE). Whole exome sequencing (WES) identified a p.Val164Aspfs (c.491-492delTG) mutation in the cAMP-dependent protein kinase A (PKA) regulatory (R) subunit 1 (PRKAR1A) gene for both the proband and her father, but not in her uncle and brother, who had not shown manifestation of cardiac myxoma by the time of this report.

INTERVENTIONS

The myxoma resection was performed following the standard procedure of open chest surgery.

OUTCOMES

The tumor was successfully removed along with the tuberculum. The patient recovered well and was discharged home. No recurrence occurred during 1-year follow-up.

LESSONS

Our findings suggest that PRKAR1A mutation (c.491_492delTG) may be associated with cardiac myxoma, and genetic counseling and specific locus mutation tests may contribute to assessing the risk of cardiac myxoma.