Co-occurrence of Proteus syndrome and ventricular tachycardia cardiac arrest in a teenager.

Proteus syndrome is an extremely rare overgrowth condition caused by a somatic variant of the AKT1 gene. It can involve multiple organ systems though rarely is there symptomatic cardiac involvement. Fatty infiltration of the myocardium has been described but has not been reported to cause functional or conduction abnormalities. We present an individual with Proteus syndrome who suffered a sudden cardiac arrest.

Late-onset Proteus syndrome with cerebriform connective tissue nevus and subsequent development of intraductal papilloma.

Proteus syndrome (PS) is a rare segmental overgrowth disorder caused by a mosaic activating variant in AKT1. The features of PS are often not present at birth but develop during the first few years of life. We describe a 55-year-old female, whose first symptom of overgrowth, a cerebriform connective tissue nevus, occurred at 19 years of age. We report the identification of the AKT1 c.49G > A p.(Glu17Lys) variant in this progressive lesion, the bony overgrowth, and recurrence after surgical intervention. In the sixth decade of life, this individual developed intraductal papillomas within her right breast which were confirmed to contain the same activating AKT1 variant as the connective tissue nevus. While similar neoplasms have been described in an individual with Proteus syndrome, none has been evaluated for the presence of the AKT1 variant. The tumor also contained two likely pathogenic variants in PIK3R1, c.1392_1403dupTAGATTATATGA p.(Asp464_Tyr467dup) and c.1728_1730delGAG p.(Arg577del). The finding of additional genetic variation putatively affecting the PI3K/AKT pathway in the neoplastic tissue may provide preliminary evidence of a molecular mechanism for tumorigenesis in PS. The late onset of symptoms and molecular characterization of the breast tumor expand the clinical spectrum of this rare disorder.

Quantification of Proteus syndrome-associated lung disease.

BACKGROUND: Proteus syndrome is an ultra-rare mosaic overgrowth disorder. Individuals with Proteus syndrome can develop emphysematous and cystic changes of the lung that may lead to progressive respiratory symptoms and require surgical intervention. This retrospective study seeks to quantify the radiographic features of Proteus syndrome-associated lung disease using computed tomography (CT) of the chest. The first method derives a Cystic Lung Score (CLS) by using a computer-aided diagnostic tool to quantify the fraction of cystic involvement of the lung. The second method yields a Clinician Visual Score (CVS), an observer reported scale of severity based on multiple radiographic features. The aim of this study was to determine if these measurements are associated with clinical symptoms, pulmonary function test (PFT) measurements, and if they may be used to assess progression of pulmonary disease. RESULTS: One hundred and thirteen imaging studies from 44 individuals with Proteus syndrome were included. Dyspnea and oxygen use were each associated with higher CLS (p = 0.001 and < 0.001, respectively) and higher CVS (p < 0.001 and < 0.001). Decreases in percent predicted FVC, FEV1, and DLCO each correlated with increased CLS and CVS. The annual increase of CLS in children, 5.6, was significantly greater than in adults, 1.6. (p = 0.03). The annual increase in CVS in children, 0.4, was similar to adults, 0.2 (p = 0.36). CONCLUSIONS: Proteus syndrome-associated lung disease is progressive. The rate of cystic progression is increased in children. Increased scores in CLS and CVS were associated with clinical symptoms and decreased pulmonary function. Both methods were able to detect change over time and were associated with clinically meaningful outcomes which may enable their use in interventional studies.

Development of the Clinical Gestalt Assessment: a visual clinical global impression scale for Proteus syndrome.

BACKGROUND: Clinical outcome assessments are important tools for measuring the natural history of disease and efficacy of an intervention. The heterogenous phenotype and difficult to quantity features of Proteus syndrome present challenges to measuring clinical outcomes. To address these, we designed a global clinical assessment for Proteus syndrome, a rare mosaic overgrowth disorder. The Clinical Gestalt Assessment (CGA) aims to evaluate change over time in this phenotypically diverse disorder. RESULTS: We gathered paired serial photographs and radiographs obtained at 12-to-36-month intervals from our natural history study of Proteus syndrome. The chronologic order of each set was blinded and presented to clinicians familiar with overgrowth disorders. They were asked to determine the chronologic order and, based on that response, rate global clinical change using a seven-point scale (Much Worse, Worse, Minimally Worse, No Change, Minimally Improved, Improved, Much Improved). Following a pilot, we tested the inter-rater reliability of the CGA using eight cases rated by eight clinicians. Raters identified the correct chronologic order in 53 of 64 (83%) of responses. There was low inter-rater variance and poor to moderate reliability with an intraclass correlation coefficient of 0.46 (95% CI 0.24-0.75). The overall estimate of global change was Minimally Worse over time, which is an accurate reflection of the natural history of Proteus syndrome. CONCLUSIONS: The CGA is a tool to evaluate clinical change over time in Proteus syndrome and may be a useful adjunct to measure clinical outcomes in prospective therapeutic trials.

Case report: five-year experience of AKT inhibition with miransertib (MK-7075) in an individual with Proteus syndrome.

Proteus syndrome is a rare overgrowth disorder caused by postzygotic activating variants in AKT1 Individuals may develop a range of skin, bone, and soft tissue overgrowth leading to functional impairment and disfigurement. Therapy for this disorder is limited to supportive care and surgical intervention. Inhibitors of AKT, originally designed as cancer therapeutics, are a rational, targeted pharmacologic strategy to mitigate the devastating morbidity of Proteus syndrome. We present the 5-yr follow-up of an 18-yr-old male with Proteus syndrome treated with miransertib (MK-7075), an oral pan-AKT inhibitor. At completion of a planned 48-wk phase 1 pharmacodynamic study, the individual derived sufficient benefit that the study was amended to permit continued use and assess the long-term safety of miransertib. The treatment has been well-tolerated with mild treatment-attributed side effects including headache, transient hyperglycemia, and transient elevations of aspartate aminotransferase, alanine aminotransferase, and bilirubin. The patient has experienced sustained improvement of pain and slowed growth of bilateral plantar cerebriform connective tissue nevi. This case report supplements the data from our prior study extending those findings out to 5 years. It shows that at the doses used, miransertib has a favorable safety profile and durable benefit of improving symptoms of pain and slowing progression of overgrowth in Proteus syndrome in a single individual. Although an uncontrolled single report cannot prove safety or efficacy, these data lend support to the encouraging preliminary data of our prior phase 1 pharmacodynamic study.