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Cavaillé M, Crampon D, Achim V, Bubien V, Uhrhammer N, Privat M, Ponelle-Chachuat F, Gay-Bellile M, Lepage M, Ouedraogo ZG, Jones N, Bidet Y, Sevenet N, Bignon YJ. Diagnosis of PTEN mosaicism: the relevance of additional tumor DNA sequencing. A case report and review of the literature. BMC Med Genomics 2023; 16:166. [PMID: 37442961 PMCID: PMC10339495 DOI: 10.1186/s12920-023-01600-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 07/05/2023] [Indexed: 07/15/2023] Open
Abstract
BACKGROUND PTEN hamartoma syndrome (PHTS) is an autosomal dominant disorder characterized by pathogenic variants in the tumor suppressor gene phosphatase and tensin homolog (PTEN). It is associated with an increased risk of muco-cutaneous features, hamartomatous tumors, and cancers. Mosaicism has been found in a few cases of patients with de novo PHTS, identified from blood samples. We report a PHTS patient with no variant identified from blood sample. Constitutional PTEN mosaicism was detected through sequencing of DNA from different tumoral and non-tumoral samples. CASE PRESENTATION Our patient presented clinical Cowden syndrome at 56 years of age, with three major criteria (macrocephaly, Lhermitte Duclos disease, oral papillomatosis), and two minor criteria (structural thyroid lesions, esophageal glycogenic acanthosis). Deep sequencing of PTEN of blood leukocytes did not reveal any pathogenic variants. Exploration of tumoral (colonic ganglioneuroma, esophageal papilloma, diapneusia fibroids) and non-tumoral stomach tissues found the same PTEN pathogenic variant (NM_000314.4 c.389G > A; p.(Arg130Gln)), with an allelic frequency of 12 to 59%, confirming genomic mosaicism for Cowden syndrome. CONCLUSIONS This case report, and review of the literature, suggests that systematic tumor analysis is essential for patients presenting PTEN hamartoma syndrome in the absence of any causal variant identified in blood leukocytes, despite deep sequencing. In 65 to 70% of cases of clinical Cowden syndrome, no pathogenic variant in the PTEN is observed in blood samples: mosaicism may explain a significant number of these patients. Tumor analysis would improve our knowledge of the frequency of de novo variations in this syndrome. Finally, patients with mosaicism for PTEN may not have a mild phenotype; medical care identical to that of heterozygous carriers should be offered.
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Affiliation(s)
- Mathias Cavaillé
- Imagerie Moléculaire Et StratégiesThéranostiques, Université Clermont Auvergne, INSERM, U1240, 63000, Clermont Ferrand, France.
- Département d'Oncogénétique, Centre Jean Perrin, 63011, Clermont-Ferrand, France.
| | - Delphine Crampon
- Service d'hépato-Gastro-Entérologie, Pôle Santé République, 63000, Clermont Ferrand, France
| | - Viorel Achim
- Service de Neurochirurgie, CHU Gabriel Montpied, 63000, Clermont Ferrand, France
| | - Virginie Bubien
- Unité d'oncogénétique, Institut Bergonié, 229 Cours de L'Argonne, 33076, Bordeaux Cedex, France
- INSERM U1218, Institut Bergonié, 229 Cours de L'Argonne, 33076, Bordeaux Cedex, France
| | - Nancy Uhrhammer
- Imagerie Moléculaire Et StratégiesThéranostiques, Université Clermont Auvergne, INSERM, U1240, 63000, Clermont Ferrand, France
- Département d'Oncogénétique, Centre Jean Perrin, 63011, Clermont-Ferrand, France
| | - Maud Privat
- Imagerie Moléculaire Et StratégiesThéranostiques, Université Clermont Auvergne, INSERM, U1240, 63000, Clermont Ferrand, France
- Département d'Oncogénétique, Centre Jean Perrin, 63011, Clermont-Ferrand, France
| | - Flora Ponelle-Chachuat
- Imagerie Moléculaire Et StratégiesThéranostiques, Université Clermont Auvergne, INSERM, U1240, 63000, Clermont Ferrand, France
- Département d'Oncogénétique, Centre Jean Perrin, 63011, Clermont-Ferrand, France
| | - Mathilde Gay-Bellile
- Imagerie Moléculaire Et StratégiesThéranostiques, Université Clermont Auvergne, INSERM, U1240, 63000, Clermont Ferrand, France
- Département d'Oncogénétique, Centre Jean Perrin, 63011, Clermont-Ferrand, France
| | - Mathis Lepage
- Imagerie Moléculaire Et StratégiesThéranostiques, Université Clermont Auvergne, INSERM, U1240, 63000, Clermont Ferrand, France
- Département d'Oncogénétique, Centre Jean Perrin, 63011, Clermont-Ferrand, France
| | | | - Natalie Jones
- Unité d'oncogénétique, Institut Bergonié, 229 Cours de L'Argonne, 33076, Bordeaux Cedex, France
- INSERM U1218, Institut Bergonié, 229 Cours de L'Argonne, 33076, Bordeaux Cedex, France
| | - Yannick Bidet
- Imagerie Moléculaire Et StratégiesThéranostiques, Université Clermont Auvergne, INSERM, U1240, 63000, Clermont Ferrand, France
- Département d'Oncogénétique, Centre Jean Perrin, 63011, Clermont-Ferrand, France
| | - Nicolas Sevenet
- Unité d'oncogénétique, Institut Bergonié, 229 Cours de L'Argonne, 33076, Bordeaux Cedex, France
- INSERM U1218, Institut Bergonié, 229 Cours de L'Argonne, 33076, Bordeaux Cedex, France
- UFR de Pharmacie, Univ. Bordeaux, 146 Rue Léo Saignat, 33076, Bordeaux Cedex, France
| | - Yves-Jean Bignon
- Imagerie Moléculaire Et StratégiesThéranostiques, Université Clermont Auvergne, INSERM, U1240, 63000, Clermont Ferrand, France
- Département d'Oncogénétique, Centre Jean Perrin, 63011, Clermont-Ferrand, France
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Chen JL, Miller DT, Schmidt LS, Malkin D, Korf BR, Eng C, Kwiatkowski DJ, Giannikou K. Mosaicism in Tumor Suppressor Gene Syndromes: Prevalence, Diagnostic Strategies, and Transmission Risk. Annu Rev Genomics Hum Genet 2022; 23:331-361. [PMID: 36044908 DOI: 10.1146/annurev-genom-120121-105450] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A mosaic state arises when pathogenic variants are acquired in certain cell lineages during postzygotic development, and mosaic individuals may present with a generalized or localized phenotype. Here, we review the current state of knowledge regarding mosaicism for eight common tumor suppressor genes-NF1, NF2, TSC1, TSC2, PTEN, VHL, RB1, and TP53-and their related genetic syndromes/entities. We compare and discuss approaches for comprehensive diagnostic genetic testing, the spectrum of variant allele frequency, and disease severity. We also review affected individuals who have no mutation identified after conventional genetic analysis, as well as genotype-phenotype correlations and transmission risk for each tumor suppressor gene in full heterozygous and mosaic patients. This review provides new insight into similarities as well as marked differences regarding the appreciation of mosaicism in these tumor suppressor syndromes.
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Affiliation(s)
- Jillian L Chen
- Cancer Genetics Laboratory, Division of Pulmonary and Critical Care Medicine and Division of Genetics, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA; .,Boston University School of Medicine, Boston, Massachusetts, USA
| | - David T Miller
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Laura S Schmidt
- Urologic Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.,Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - David Malkin
- Division of Haematology/Oncology, The Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Bruce R Korf
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Charis Eng
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.,Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, USA.,Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.,Germline High Risk Cancer Focus Group, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, USA
| | - David J Kwiatkowski
- Cancer Genetics Laboratory, Division of Pulmonary and Critical Care Medicine and Division of Genetics, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA;
| | - Krinio Giannikou
- Cancer Genetics Laboratory, Division of Pulmonary and Critical Care Medicine and Division of Genetics, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA; .,Division of Hematology and Oncology, Cancer and Blood Disease Institute, Children's Hospital Los Angeles, Los Angeles, California, USA;
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3
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Catch them if you are aware: PTEN postzygotic mosaicism in clinically suspicious patients with PTEN Hamartoma Tumour Syndrome and literature review. Eur J Med Genet 2022; 65:104533. [DOI: 10.1016/j.ejmg.2022.104533] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/19/2022] [Accepted: 05/26/2022] [Indexed: 12/12/2022]
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Jansen AML, Goel A. Mosaicism in Patients With Colorectal Cancer or Polyposis Syndromes: A Systematic Review. Clin Gastroenterol Hepatol 2020; 18:1949-1960. [PMID: 32147591 PMCID: PMC7725418 DOI: 10.1016/j.cgh.2020.02.049] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 02/09/2020] [Accepted: 02/14/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Somatic mosaicism, in which variants arise post-zygotically and are therefore not present in all cells in the body, may be an underestimated cause of colorectal cancer (CRC) and polyposis syndromes. We performed a systematic review to provide a comprehensive overview of somatic mosaicism in patients with CRC and polyposis syndromes. METHODS We searched PubMed through March 2018 to identify reports of mosaicism in patients with CRC or polyposis syndromes. We divided the final set of studies into 3 subgroups describing APC mosaicism, mosaicism in other CRC susceptibility genes, and epigenetic mosaicism. RESULTS Of the 232 articles identified in our systematic search, 46 met the criteria for further analysis. Of these, 35 studies described mosaic variants or epimutations in patients with CRC or polyposis syndromes. Nineteen studies described APC mosaicism, comprising a total of 57 patients. Six described mosaicism in genes associated with familial CRC syndromes, such as Lynch and Cowden syndromes. Ten studies described epigenetic mosaicism, sometimes resulting from a germline variant (such as deletion of EPCAM). CONCLUSIONS We found that somatic mosaicism is underdiagnosed but critical for determining the clinical management of patients with de novo polyposis who possibly carry mosaic APC variants, and present a decision tree for the clinical management of these patients. Mosaicism in genes associated with susceptibility to CRC contributes to development of other familial CRC syndromes. Heritable epigenetic mosaicism is likely underestimated and could have a dominant pattern of inheritance. However, the inheritance of primary mosaic epimutations, without an underlying genetic cause, is complex and not fully understood.
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Affiliation(s)
- Anne Maria Lucia Jansen
- Center for Gastrointestinal Research, Center for Translational Genomics and Oncology, Baylor Scott & White Research Institute and Charles A. Sammons Cancer Center, Dallas, Texas
| | - Ajay Goel
- Center for Gastrointestinal Research, Center for Translational Genomics and Oncology, Baylor Scott & White Research Institute and Charles A. Sammons Cancer Center, Dallas, Texas; Department of Molecular Diagnostics and Experimental Therapeutics, Beckman Research Institute of City of Hope, Duarte, California.
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Mosaic PTEN alteration in the neural crest during embryogenesis results in multiple nervous system hamartomas. Acta Neuropathol Commun 2019; 7:191. [PMID: 31796102 PMCID: PMC6892231 DOI: 10.1186/s40478-019-0841-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 11/06/2019] [Indexed: 11/10/2022] Open
Abstract
The contribution of mosaic alterations to tumors of the nervous system and to non-malignant neurological diseases has been unmasked thanks to the development of Next Generation Sequencing (NGS) technologies. We report here the case of a young patient without any remarkable familial medical history who was first referred at 7 years of age, for an autism spectrum disorder (ASD) of Asperger type, not associated with macrocephaly. The patient subsequently presented at 10 years of age with multiple nodular lesions located within the trigeminal, facial and acoustic nerve ganglia and at the L3 level. Histological examination of this latter lesion revealed a glioneuronal hamartoma, exhibiting heterogeneous PTEN immunoreactivity, astrocyte and endothelial cell nuclei expressing PTEN, but not ganglion cells. NGS performed on the hamartoma allowed the detection of a PTEN pathogenic variant in 30% of the reads. The presence of this variant in the DNA extracted from blood and buccal swabs in 3.5 and 11% of the NGS reads, respectively, confirmed the mosaic state of the PTEN variant. The anatomical distribution of the lesions suggests that the mutational event affecting PTEN occurred in neural crest progenitors, thus explaining the absence of macrocephaly. This report shows that mosaic alteration of PTEN may result in multiple central and peripheral nervous system hamartomas and that the presence of such alteration should be considered in patients with multiple nervous system masses, even in the absence of cardinal features of PTEN hamartoma tumor syndrome, especially macrocephaly.
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Hehir-Kwa JY, Tops BBJ, Kemmeren P. The clinical implementation of copy number detection in the age of next-generation sequencing. Expert Rev Mol Diagn 2018; 18:907-915. [PMID: 30221560 DOI: 10.1080/14737159.2018.1523723] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
INTRODUCTION The role of copy number variants (CNVs) in disease is now well established. In parallel NGS technologies, such as long-read technologies, there is continual development and data analysis methods continue to be refined. Clinical exome sequencing data is now a reality for many diagnostic laboratories in both congenital genetics and oncology. This provides the ability to detect and report both SNVs and structural variants, including CNVs, using a single assay for a wide range of patient cohorts. Areas covered: Currently, whole-genome sequencing is mainly restricted to research applications and clinical utility studies. Furthermore, detecting the full-size spectrum of CNVs as well as somatic events remains difficult for both exome and whole-genome sequencing. As a result, the full extent of genomic variants in an individual's genome is still largely unknown. Recently, new sequencing technologies have been introduced which maintain the long-range genomic context, aiding the detection of CNVs and structural variants. Expert commentary: The development of long-read sequencing promises to resolve many CNV and SV detection issues but is yet to become established. The current challenge for clinical CNV detection is how to fully exploit all the data which is generated by high throughput sequencing technologies.
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Affiliation(s)
- Jayne Y Hehir-Kwa
- a Princess Máxima Center for Pediatric Oncology , Utrecht , Netherlands
| | - Bastiaan B J Tops
- a Princess Máxima Center for Pediatric Oncology , Utrecht , Netherlands
| | - Patrick Kemmeren
- a Princess Máxima Center for Pediatric Oncology , Utrecht , Netherlands
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Nakayama T, Ishii A, Yoshida T, Nasu H, Shimojima K, Yamamoto T, Kure S, Hirose S. Somatic mosaic deletions involving SCN1A
cause Dravet syndrome. Am J Med Genet A 2018; 176:657-662. [DOI: 10.1002/ajmg.a.38596] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 10/09/2017] [Accepted: 12/07/2017] [Indexed: 12/19/2022]
Affiliation(s)
- Tojo Nakayama
- Department of Pediatrics; Tohoku University School of Medicine; Sendai Japan
| | - Atsushi Ishii
- Department of Pediatrics; School of Medicine; Fukuoka University; Fukuoka Japan
- Central Research Institute for the Molecular Pathomechanisms of Epilepsy; Fukuoka University; Fukuoka Japan
| | - Takeshi Yoshida
- Department of Pediatrics; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - Hirosato Nasu
- National Epilepsy Center; Shizuoka Institute of Epilepsy and Neurological Disorders; Shizuoka Japan
| | - Keiko Shimojima
- Tokyo Women's Medical University Institute for Integrated Medical Sciences; Tokyo Japan
| | - Toshiyuki Yamamoto
- Tokyo Women's Medical University Institute for Integrated Medical Sciences; Tokyo Japan
| | - Shigeo Kure
- Department of Pediatrics; Tohoku University School of Medicine; Sendai Japan
| | - Shinichi Hirose
- Department of Pediatrics; School of Medicine; Fukuoka University; Fukuoka Japan
- Central Research Institute for the Molecular Pathomechanisms of Epilepsy; Fukuoka University; Fukuoka Japan
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Somatic TP53 variants frequently confound germ-line testing results. Genet Med 2017; 20:809-816. [PMID: 29189820 PMCID: PMC5976505 DOI: 10.1038/gim.2017.196] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 10/06/2017] [Indexed: 12/11/2022] Open
Abstract
Purpose Blood/saliva DNA is thought to represent the germline in genetic cancer risk assessment. Cases with pathogenic TP53 variants detected by multi-gene panel tests (MGPT) are often discordant with Li-Fraumeni Syndrome (LFS), raising concern about misinterpretation of acquired aberrant clonal expansions (ACE) with TP53 variants as germline results. Methods Pathogenic TP53 variants with abnormal next-generation sequencing (NGS) metrics (e.g., decreased ratio [<25%] of mutant to wild-type allele, >2 detected alleles) were selected from a CLIA laboratory testing cohort. Alternate tissues and/or close relatives were tested to discern between ACE and germline status. Clinical data and LFS testing criteria were examined. Results Among 114,630 MGPT and 1,454 TP53 gene-specific analyses, abnormal NGS metrics were observed in 20% of 353 TP53 positive results, and ACE was confirmed for 91% of cases with ancillary materials, most due to clonal hematopoiesis. Only four met Chompret criteria. ACE cases were older (50 years vs 33.7; P = 0.02) and were more frequent among MGPT (66/285; 23.2%) vs TP53 gene-specific tests (6/68; 8.8%, P = 0.005). Conclusion ACE confounds germline diagnosis, may portend hematologic malignancy, and may result in unwarranted clinical interventions. Ancillary testing to confirm germline status should precede Li-Fraumeni syndrome management.
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Rapid detection of germline mutations for hereditary gastrointestinal polyposis/cancers using HaloPlex target enrichment and high-throughput sequencing technologies. Fam Cancer 2017; 15:553-62. [PMID: 26837502 DOI: 10.1007/s10689-016-9872-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Genetic testing for hereditary colorectal polyposis/cancers has become increasingly important. Therefore, the development of a timesaving diagnostic platform is indispensable for clinical practice. We designed and validated target enrichment sequencing for 20 genes implicated in familial gastrointestinal polyposis/cancers in 32 cases with previously confirmed mutations using the HaloPlex enrichment system and MiSeq. We demonstrated that HaloPlex captured the targeted regions with a high efficiency (99.66 % for covered target regions, and 99.998 % for breadth of coverage), and MiSeq achieved a high sequencing accuracy (98.6 % for the concordant rate with SNP arrays). Using this approach, we correctly identified 33/33 (100 %) confirmed alterations including SNV, small INDELs and large deletions, and insertions in APC, BMPR1A, EPCAM, MLH1, MSH2, MSH6, PMS2, and SKT11. Our approach yielded the sequences of 20 target genes in a single experiment, and correctly identified all previously known mutations. Our results indicate that our approach successfully detected a wide range of genetic variations in a short turnaround time and with a small sample size for the rapid screening of known causative gene mutations of inherited colon cancer, such as familial adenomatous polyposis, Lynch syndrome, Peutz-Jeghers syndrome, and Juvenile polyposis syndrome.
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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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Molecular Genetics of the PI3K-AKT-mTOR Pathway in Genodermatoses: Diagnostic Implications and Treatment Opportunities. J Invest Dermatol 2016; 136:15-23. [PMID: 26763419 DOI: 10.1038/jid.2015.331] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 06/12/2015] [Accepted: 06/30/2015] [Indexed: 01/19/2023]
Abstract
A number of critical signaling pathways are required for homeostatic regulation of cell survival, differentiation, and proliferation during organogenesis. One of them is the PI3K-AKT-mTOR pathway consisting of a cascade of inhibitor/activator molecules. Recently, a number of heritable diseases with skin involvement, manifesting particularly with tissue overgrowth, have been shown to result from mutations in the genes in the PI3K-AKT-mTOR and interacting intracellular pathways. Many of these conditions represent an overlapping spectrum of phenotypic manifestations forming a basis for novel, unifying classifications. Identification of the mutant genes and specific mutations in these patients has implications for diagnostics and genetic counseling and provides a rational basis for the development of novel treatment modalities for this currently intractable group of disorders.
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Abstract
Diversity is the basis of fitness selection. Although the genome of an individual is considered to be largely stable, there is theoretical and experimental evidence--both in model organisms and in humans--that genetic mosaicism is the rule rather than the exception. The continuous generation of cell variants, their interactions and selective pressures lead to life-long tissue dynamics. Individuals may thus enjoy 'clonal health', defined as a clonal composition that supports healthy morphology and physiology, or suffer from clonal configurations that promote disease, such as cancer. The contribution of mosaicism to these processes starts during embryonic development. In this Opinion article, we argue that the road to cancer might begin during these early stages.
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Affiliation(s)
- Luis C Fernández
- Epithelial Carcinogenesis Group, Cancer Cell Biology Programme, Spanish National Cancer Research Centre-CNIO, Melchor Fernández Almagro 3, 28029 Madrid, Spain
| | - Miguel Torres
- Centro Nacional de Investigaciones Cardiovasculares-CNIC, Melchor Fernández Almagro 3, 28029 Madrid, Spain
| | - Francisco X Real
- Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, and at the Epithelial Carcinogenesis Group, Cancer Cell Biology Programme, Spanish National Cancer Research Centre-CNIO, 28029 Madrid, Spain
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Erickson RP. Recent advances in the study of somatic mosaicism and diseases other than cancer. Curr Opin Genet Dev 2014; 26:73-8. [DOI: 10.1016/j.gde.2014.06.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 03/27/2014] [Accepted: 06/02/2014] [Indexed: 02/06/2023]
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