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Baker TG, Glen WB, Wilson RC, Batalis NI, Wolff DJ, Welsh CT. Postmortem Diagnosis of the Proteus Syndrome by Next Generation Sequencing of Affected Brain Tissue. Acad Forensic Pathol 2022; 12:52-57. [PMID: 35799996 PMCID: PMC9254014 DOI: 10.1177/19253621221097294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 04/08/2022] [Indexed: 11/15/2022]
Abstract
We report a case of a somatic overgrowth syndrome diagnosed at forensic autopsy with the aid of next generation sequencing as Proteus syndrome. Somatic overgrowth syndromes result from spontaneous somatic mutations that arise early in development and display a mosaic pattern of expression in patient tissues. Due to the temporal and anatomic heterogeneity of these syndromes, phenotypes vary widely, resulting in clinical overlap. Furthermore, the variable ratio of mutated to nonmutated cells in patient tissue can result in low-level mutations that could be missed using Sanger sequencing. Due to these factors, recent literature points to next generation sequencing (NGS) as an adjunct to diagnosis of these rare entities. A male in his fourth decade of life presented to our forensic autopsy service with physical features suggestive of a somatic overgrowth syndrome. Due to the paucity of clinical information accompanying the individual, a definitive diagnosis based on physical characteristics, alone, was not possible. Next generation sequencing of affected formalin-fixed and paraffin-embedded brain tissue confirmed the presence of the variant in AKT1 (c.49G>A, p.Glu17Lys, in 14.13% of reads) found in Proteus syndrome. To our knowledge, this is the first report of the mosaic variant of AKT1 detected in brain tissue and the first reported case of a postmortem diagnosis of Proteus syndrome with the aid of NGS. We conclude that NGS can be used as an adjunctive method to support a specific diagnosis among the somatic overgrowth syndromes postmortem in the absence of sufficient clinical history.
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Affiliation(s)
- Tiffany G. Baker
- Tiffany G. Baker, MD, PhD,
Department of Pathology and Laboratory Medicine, Medical University of
South Carolina, Charleston, SC;
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Nathan N, Keppler-Noreuil KM, Biesecker LG, Moss J, Darling TN. Mosaic Disorders of the PI3K/PTEN/AKT/TSC/mTORC1 Signaling Pathway. Dermatol Clin 2017; 35:51-60. [PMID: 27890237 PMCID: PMC5130114 DOI: 10.1016/j.det.2016.07.001] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Somatic mutations in genes of the PI3K/PTEN/AKT/TSC/mTORC1 signaling pathway cause segmental overgrowth, hamartomas, and malignant tumors. Mosaicism for activating mutations in AKT1 or PIK3CA cause Proteus syndrome and PIK3CA-Related Overgrowth Spectrum, respectively. Postzygotic mutations in PTEN or TSC1/TSC2 cause mosaic forms of PTEN hamartoma tumor syndrome or tuberous sclerosis complex, respectively. Distinct features observed in these mosaic conditions in part reflect differences in embryological timing or tissue type harboring the mutant cells. Deep sequencing of affected tissue is useful for diagnosis. Drugs targeting mTORC1 or other points along this signaling pathway are in clinical trials to treat these disorders.
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Affiliation(s)
- Neera Nathan
- Department of Dermatology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA
| | - Kim M Keppler-Noreuil
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, Building 49, Room 4A56, 49 Convent Drive, National Institutes of Health, Bethesda, MD 20892, USA
| | - Leslie G Biesecker
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, Building 49, Room 4A56, 49 Convent Drive, National Institutes of Health, Bethesda, MD 20892, USA
| | - Joel Moss
- Cardiovascular and Pulmonary Branch, National Heart, Lung, and Blood Institute, Building 10, Room 6D05, 10 Center Drive, National Institutes of Health, Bethesda, MD 20892-1590, USA
| | - Thomas N Darling
- Department of Dermatology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.
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Abstract
Proteus syndrome is an extremely rare mosaic condition characterized by progressive overgrowth of tissues due to a somatic activating mutation of the AKT1 gene. Distinct cutaneous features, including cerebriform connective tissue nevi, epidermal nevi, vascular malformations, and adipose abnormalities, can alert the dermatologist to the underlying condition before the onset of asymmetric skeletal overgrowth. We present a series of photographs documenting the skin and musculoskeletal changes in a patient with Proteus syndrome over the first 2 years of life to emphasize the key signs that a dermatologist can recognize to facilitate an earlier diagnosis in these patients.
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Affiliation(s)
| | | | | | - Loretta S Davis
- Division of Dermatology, Augusta University, Augusta, Georgia
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Doucet ME, Bloomhardt HM, Moroz K, Lindhurst MJ, Biesecker LG. Lack of mutation-histopathology correlation in a patient with Proteus syndrome. Am J Med Genet A 2016; 170:1422-1432. [PMID: 27112325 DOI: 10.1002/ajmg.a.37612] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 02/22/2016] [Indexed: 11/06/2022]
Abstract
Proteus syndrome (PS) is characterized by progressive, disproportionate, segmental overgrowth, and tumor susceptibility caused by a somatic mosaic AKT1 activating mutation. Each individual has unique manifestations making this disorder extremely heterogeneous. We correlated three variables in 38 tissue samples from a patient who died with PS: the gross affection status, the microscopic affection status, and the mutation level. The AKT1 mutation was measured using a PCR-based RFLP assay. Thirteen samples were grossly normal; six had detectable mutation (2-29%) although four of these six were histopathologically normal. Of the seven grossly normal samples that had no mutation, only four were histologically normal. The mutation level in the grossly abnormal samples was 3-35% and all but the right and left kidneys, skull, and left knee bone, with mutation levels of 19%, 15%, 26%, and 17%, respectively, had abnormal histopathology. The highest mutation level was in a toe bone sample whereas the lowest levels were in the soft tissue surrounding that toe, and an omental fat nodule. We also show here that PS overgrowth can be caused by cellular proliferation or by extracellular matrix expansion. Additionally, papillary thyroid carcinoma was identified, a tumor not previously associated with PS. We conclude that gross pathology and histopathology correlate poorly with mutation levels in PS, that overgrowth can be mediated by cellular proliferation or extracellular matrix expansion, and that papillary thyroid carcinoma is part of the tumor susceptibility of PS. New methods need to be developed to facilitate genotype-phenotype correlation in mosaic disorders. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Meggie E Doucet
- Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, New Orleans, Louisiana
| | - Hadley M Bloomhardt
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, Bethesda, Maryland
| | - Krzysztof Moroz
- Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, New Orleans, Louisiana
| | - Marjorie J Lindhurst
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, Bethesda, Maryland
| | - Leslie G Biesecker
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, Bethesda, Maryland
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Valéra MC, Vaysse F, Bieth E, Longy M, Cances C, Bailleul-Forestier I. Proteus syndrome: Report of a case with AKT1 mutation in a dental cyst. Eur J Med Genet 2015; 58:300-4. [PMID: 25782637 DOI: 10.1016/j.ejmg.2015.02.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 02/18/2015] [Indexed: 01/16/2023]
Abstract
Proteus syndrome (PS) is a sporadic and rare congenital disorder characterized by a patchy or mosaic postnatal overgrowth, sometimes involving the face. The onset of overgrowth typically occurs in infancy and can commonly involve skin, connective tissue, central nervous system, eyes and viscera. The progressive overgrowth causes severe complications, such as skeletal deformities, cystic lung disease, invasive lipomas, connective tissue hyperplasia, benign and malignant tumours and deep venous thrombosis with pulmonary embolism, which can cause premature death. This disorder is caused by somatic mosaicism for a specific activating AKT1 mutation that would be lethal in a non-mosaic state. In this report, current knowledge of the aetiology, the diagnosis and the craniofacial manifestations of the disorder are reviewed. The short-term management of a 7-year-old patient with unusual oral manifestations is described. For the first time mutation of AKT1 (c.49G > A) gene was detected both in cranial exostosis and in central odontogenic fibroma of the lower jaw.
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Affiliation(s)
- Marie-Cécile Valéra
- University Paul Sabatier, Toulouse III, France; Department of Paediatric Dentistry, CHU of Toulouse, Toulouse, France; INSERM U1048, I2MC, Toulouse, France.
| | - Fréderic Vaysse
- University Paul Sabatier, Toulouse III, France; Department of Paediatric Dentistry, CHU of Toulouse, Toulouse, France
| | - Eric Bieth
- University Paul Sabatier, Toulouse III, France; Department of Genetics, CHU of Toulouse, Toulouse, France
| | - Michel Longy
- Cancer Genetics Unit, Institut Bergonié, Bordeaux, France; INSERM U916, University of Bordeaux, Bordeaux, France
| | - Claude Cances
- Department of Neuropaediatry, CHU of Toulouse, Toulouse, France
| | - Isabelle Bailleul-Forestier
- University Paul Sabatier, Toulouse III, France; Department of Paediatric Dentistry, CHU of Toulouse, Toulouse, France; LU 51, Faculty of Dentistry, Toulouse, France
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Abstract
The term epidermal nevus syndrome (ENS) has been used to describe the association of epidermal hamartomas and extracutaneous abnormalities. Although many continue to use the term "ENS," it is now understood that this is not one disease, but rather a heterogeneous group with distinct genetic profiles defined by a common cutaneous phenotype: the presence of epidermal and adnexal hamartomas that are associated with other organ system involvement. One commonality is that epidermal nevi often follow the lines of Blaschko and it appears the more widespread the cutaneous manifestations, the greater the risk for extracutaneous manifestations. The majority of the extracutaneous manifestations involve the brain, eye, and skeletal systems. The CNS involvement is wide ranging and involves both clinical manifestations such as intellectual disability and seizures, as well as structural anomalies. Several subsets of ENS with characteristic features have been delineated including the nevus sebaceus syndrome, Proteus syndrome, CHILD syndrome, Becker's nevus syndrome, nevus comedonicus syndrome, and phakomatosis pigmentokeratotica. Advances in molecular biology have revealed that the manifestations of ENS are due to genomic mosaicism. It is likely that the varied clinical manifestations of ENS are due in great part to the functional effects of specific genetic defects. Optimal management of the patient with ENS involves an interdisciplinary approach given the potential for multisystem involvement. Of note, epidermal nevi have been associated with both benign and malignant neoplasms, and thus ongoing clinical follow-up is required.
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Affiliation(s)
- Sarah Asch
- Department of Dermatology, University of California San Francisco, San Francisco, CA, USA
| | - Jeffrey L Sugarman
- Departments of Dermatology and Community and Family Medicine, University of California San Francisco, Santa Rosa, CA, USA.
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Kubota Y, Mitsukawa N, Uchida M, Uchida Y, Akita S, Hasegawa M, Satoh K. Low-level mesodermal somatic mutation mosaicism: late-onset craniofacial and cervical spinal hyperostoses. Am J Med Genet A 2013; 164A:741-7. [PMID: 24357582 DOI: 10.1002/ajmg.a.36310] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 09/24/2013] [Accepted: 10/03/2013] [Indexed: 12/22/2022]
Abstract
Craniofacial and cervical spinal hyperostoses are rarely seen in the absence of other abnormalities. Only seven patients with isolated cranial hyperostoses have been reported, and only a single patient with both calvarial and cervical vertebral hyperostoses. We report on an adult with late-onset right-sided asymmetrical hyperostoses of the cranium, mandible, and cervical vertebrae in the absence of an AKT1 mutation. At presentation, the patient displayed neither generalized overgrowth nor dysregulated adipose tissue. Standard polymerase chain reaction and Sanger sequencing of DNA extracted from formalin-fixed paraffin-embedded frontal bone and mandibular angular bone was negative for an AKT1 mutation. Though the patient's clinical manifestations did not fulfill the consensus diagnostic criteria of Proteus syndrome, the mosaic distribution of lesions, the sporadic occurrence, and the patient's progressive course were consistent with a somatic mosaicism similar to that syndrome. Hence, the patient's phenotype may have been caused by a very late mesodermal somatic mutation during embryogenesis.
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Affiliation(s)
- Yoshitaka Kubota
- Department of Plastic Surgery, Chiba University, Chiba-city, Chiba, Japan
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AKT1 gene mutation levels are correlated with the type of dermatologic lesions in patients with Proteus syndrome. J Invest Dermatol 2013; 134:543-546. [PMID: 23884311 PMCID: PMC3868633 DOI: 10.1038/jid.2013.312] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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