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Tian QJ, Zhang LJ, Zhang Q, Liu FC, Xie M, Cai JZ, Rao W. Protein-losing enteropathy and multiple vasculature dysplasia in LZTR1-related Noonan syndrome: A case report and review of literature. World J Gastroenterol 2025; 31. [DOI: 10.3748/wjg.v31.i17.105347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2025] [Revised: 03/31/2025] [Accepted: 04/21/2025] [Indexed: 04/29/2025] Open
Abstract
BACKGROUND
Protein-losing enteropathy (PLE) is a rare cause of hypoalbuminemia that can be attributed to intestinal lymphangiectasia. Patients with Noonan syndrome may present with disorder of lymph vessel formation. However, PLE is rarely reported with Noonan syndrome.
CASE SUMMARY
A 15-year-old female was hospitalized multiple times for recurrent edema and diarrhea secondary to hypoalbuminemia. Additional manifestations included a ventricular septal defect at birth, intermuscular hemangioma, slightly wide interocular and intermammary distances, and absence of the distal phalanx of the left little finger since birth. Abdominal computed tomography revealed cavernous transformation of the portal vein, and liver biopsy indicated “porto-sinusoidal vascular disease”. Whole exome and Sanger sequencing revealed a heterozygous mutation (exon9: C.850C>T:P.R284C) in leucine zipper-like transcription regulator 1, suggesting Noonan syndrome type 10. Further examinations revealed thoracic duct dysplasia and intestinal lymphangiectasia causing PLE in this patient. A multidisciplinary team decided to address thoracic duct dysplasia with outlet obstruction. Approximately two years after the microsurgical relief of the thoracic duct outlet obstruction, the patient achieved persistent normal serum albumin level without edema or diarrhea. Furthermore, the relevant literatures on Noonan syndrome and PLE were reviewed.
CONCLUSION
Herein, we reported the first case of PLE associated with Noonan syndrome caused by a rare genetic mutation in leucine zipper-like transcription regulator 1 (c.850C>T:P.R284C) with newly reported manifestations. This case presented the successful treatment of clinical hypoalbuminemia attributed to thoracic duct dysplasia, intestinal lymphangiectasia and PLE.
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Affiliation(s)
- Qiu-Ju Tian
- Division of Hepatology, Liver Disease Center, The Affiliated Hospital of Qingdao University, Qingdao 266100, Shandong Province, China
- Organ Transplantation Center, The Affiliated Hospital of Qingdao University, Qingdao 266100, Shandong Province, China
| | - Lu-Jia Zhang
- Department of Urology, Qingdao Municipal Hospital, University of Health and Rehabilitation Sciences, Qingdao 266100, Shandong Province, China
| | - Qun Zhang
- Division of Hepatology, Liver Disease Center, The Affiliated Hospital of Qingdao University, Qingdao 266100, Shandong Province, China
- Organ Transplantation Center, The Affiliated Hospital of Qingdao University, Qingdao 266100, Shandong Province, China
| | - Feng-Chao Liu
- Division of Hepatology, Liver Disease Center, The Affiliated Hospital of Qingdao University, Qingdao 266100, Shandong Province, China
- Organ Transplantation Center, The Affiliated Hospital of Qingdao University, Qingdao 266100, Shandong Province, China
| | - Man Xie
- Department of Gastroenterology, The Affiliated Hospital of Qingdao University, Qingdao 266100, Shandong Province, China
| | - Jin-Zhen Cai
- Organ Transplantation Center, The Affiliated Hospital of Qingdao University, Qingdao 266100, Shandong Province, China
| | - Wei Rao
- Division of Hepatology, Liver Disease Center, The Affiliated Hospital of Qingdao University, Qingdao 266100, Shandong Province, China
- Organ Transplantation Center, The Affiliated Hospital of Qingdao University, Qingdao 266100, Shandong Province, China
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2
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Nagasaka S, Phi JH. Genetic Basis and Clinical Management of Schwannomatosis. J Korean Neurosurg Soc 2025; 68:286-293. [PMID: 40049215 PMCID: PMC12062529 DOI: 10.3340/jkns.2025.0001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2025] [Revised: 03/04/2025] [Accepted: 03/04/2025] [Indexed: 05/10/2025] Open
Abstract
Schwannomatosis (SWN) is now recognized as a broad classification that includes neurofibromatosis (NF) type 2, reflecting their shared genetic and phenotypic characteristics. Previously, SWN and NF type 2 were considered distinct clinical entities; however, the 2022 classification revision has unified them under the umbrella of SWN, with NF type 2 now referred to as NF2-related SWN. SWN arises from mutations in NF2, SMARCB1 (SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily b, member 1) or LZTR1 (leucine zipper like transcription regulator 1). Recent diagnostic criteria for SWN incorporate molecular classification, including "NF2-related SWN", "SMARCB1-related SWN", "LZTR1-related SWN", "22q-related SWN", "SWN-not otherwise specified", or "SWN-not elsewhere classified". NF2-related SWN is a genetic condition where all individuals with a germline or constitutional NF2 mutation are destined to develop the disease. The pathogenesis of SMARCB1- or LZTR1-related SWN follows a three-step, four-hit model. This involves retention of the mutated germline SMARCB1 or LZTR1 allele in the tumor, loss of the wild-type chromosome 22, and somatic mutation in the NF2 gene. Clinically, NF2-related SWN involves bilateral vestibular schwannomas, with treatment options including microsurgery, radiotherapy, and bevacizumab, each with specific benefits and limitations. Patients with SWN frequently present with chronic pain caused by schwannomas, which often does not correlate with tumor size, location, or burden. Management of SWN is primarily symptom-based. Surgical intervention is reserved for symptomatic lesions, particularly in cases of spinal cord compression or significant functional impairments. Multidisciplinary approaches to pain management are critical for enhancing quality of life. Although malignant transformation of schwannomas is a potential risk, the life expectancy of individuals with SWN is nearly normal. Despite advancements in understanding SWN, further research is necessary to elucidate the underlying genetic mechanisms and to develop targeted therapeutic strategies for this complex disorder.
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Affiliation(s)
- Shohei Nagasaka
- Department of Neurosurgery, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Ji Hoon Phi
- Division of Pediatric Neurosurgery, Seoul National University Children’s Hospital, Seoul National University College of Medicine, Seoul, Korea
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3
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Huong QTT, Truc LTN, Ueda H, Fukui K, Higasa K, Sato Y, Takeda S, Hattori M, Tsukaguchi H. Nerve Enlargement in Patients with INF2 Variants Causing Peripheral Neuropathy and Focal Segmental Glomerulosclerosis. Biomedicines 2025; 13:127. [PMID: 39857711 PMCID: PMC11763285 DOI: 10.3390/biomedicines13010127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2024] [Revised: 12/23/2024] [Accepted: 12/29/2024] [Indexed: 01/27/2025] Open
Abstract
Background: Charcot-Marie-Tooth (CMT) disease is an inherited peripheral neuropathy primarily involving motor and sensory neurons. Mutations in INF2, an actin assembly factor, cause two diseases: peripheral neuropathy CMT-DIE (MIM614455) and/or focal segmental glomerulosclerosis (FSGS). These two phenotypes arise from the progressive degeneration affecting podocytes and Schwann cells. In general, nerve enlargement has been reported in 25% of the demyelinating CMT subtype (CMT1), while little is known about the CMT-DIE caused by INF2 variants. Methods: To characterize the peripheral nerve phenotype of INF2-related CMT, we studied the clinical course, imaging, histology, and germline genetic variants in two unrelated CMT-DIE patients. Results: Patient 1 (INF2 p.Gly73Asp) and patient 2 (p.Val108Asp) first noticed walking difficulties at 10 to 12 years old. Both of them were electrophysiologically diagnosed with demyelinating neuropathy. In patient 2, the sural nerve biopsy revealed an onion bulb formation. Both patients developed nephrotic syndrome almost simultaneously with CMT and progressed into renal failure at the age of 16 to 17 years. Around the age of 30 years, both patients manifested multiple hypertrophy of the trunk, plexus, and root in the cervical, brachial, lumbosacral nerves, and cauda equina. The histology of the cervical mass in patient 2 revealed Schwannoma. Exome analysis showed that patient 2 harbors a germline LZTR1 p.Arg68Gly variant, while patient 1 has no schwannomatosis-related mutations. Conclusions: Peripheral neuropathy caused by INF2 variants may lead to the development of multifocal hypertrophy with age, likely due to the initial demyelination and subsequent Schwann cell proliferation. Schwannoma could co-occur when the tissues attain additional hits in schwannomatosis-related genes (e.g., LZTR1).
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Affiliation(s)
- Quynh Tran Thuy Huong
- Second Department of Internal Medicine, Division of Nephrology, Kansai Medical University, Hirakata 573-1010, Japan
| | - Linh Tran Nguyen Truc
- Second Department of Internal Medicine, Division of Nephrology, Kansai Medical University, Hirakata 573-1010, Japan
- Department of Internal Medicine, Pham Ngoc Thach University of Medicine, Ho Chi Minh 70000, Vietnam
| | - Hiroko Ueda
- Second Department of Internal Medicine, Division of Nephrology, Kansai Medical University, Hirakata 573-1010, Japan
| | - Kenji Fukui
- Department of Biochemistry, Faculty of Medicine, Osaka Medical and Pharmaceutical University, Takatsuki 569-8686, Japan
| | - Koichiro Higasa
- Department of Genome Analysis, Institute of Biomedical Science, Kansai Medical University, Hirakata 573-1010, Japan
| | - Yoshinori Sato
- Department of Medicine, Division of Nephrology, Showa University School of Medicine, Fujigaoka Hospital, Yokohama 227-8501, Japan
| | - Shinichi Takeda
- Internal Medicine, Kurobe City Hospital, Toyama 938-8502, Japan
| | - Motoshi Hattori
- Department of Pediatric Nephrology, Tokyo Women’s Medical University, Tokyo 162-8666, Japan
| | - Hiroyasu Tsukaguchi
- Second Department of Internal Medicine, Division of Nephrology, Kansai Medical University, Hirakata 573-1010, Japan
- Clinical Genetics Center, Kansai Medical University Hospital, Hirakata 573-1010, Japan
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4
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Draaisma F, Leenders EKSM, Erasmus CE, Braakman HMH, Burgers MCJ, Coppens CH, Rinne T, Zenker M, Tartaglia M, Reintjes W, Voermans NC, van Engelen BGM, van Alfen N, Draaisma JMT. Nerve enlargement in patients with Noonan syndrome: A retrospective cohort study. Am J Med Genet A 2024; 194:e63810. [PMID: 38958480 DOI: 10.1002/ajmg.a.63810] [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: 04/15/2024] [Revised: 06/08/2024] [Accepted: 06/22/2024] [Indexed: 07/04/2024]
Abstract
Noonan syndrome (NS) is an autosomal dominant condition characterized by facial dysmorphism, congenital heart disease, development delay, growth retardation and lymphatic disease. It is caused by germline pathogenic variants in genes encoding proteins in the Ras/mitogen-activated protein kinase signaling pathway. Nerve enlargement is not generally considered as a feature of NS, although some cases have been reported. High-resolution nerve ultrasound enables detailed anatomical assessment of peripheral nerves and can show enlarged nerves. This retrospective cohort study aims to describe the sonographic findings of patients with NS performed during a 1-year time period. Data on the degree of enlargement, the relation to increasing age, pain in extremities, genotype on the gene level and clinical features were collected. Twenty-nine of 93 patients visiting the NS Center of Expertise of the Radboud University Medical Center Nijmegen underwent high-resolution ultrasound. In 24 patients (83%) nerve enlargement was found. Most of them experienced pain. We observed a weak correlation with increasing age and the degree of nerve enlargement but no association with pain, genotype at the gene level or clinical features. This study shows that patients with NS have a high predisposition for sonographic nerve enlargement and that the majority experience pain.
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Affiliation(s)
- Fieke Draaisma
- Department of Pediatrics, Radboud Institute for Health Sciences, Radboud University Medical Center, Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Erika K S M Leenders
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Corrie E Erasmus
- Department of Pediatric Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen Medical Center, Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Hilde M H Braakman
- Department of Pediatric Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen Medical Center, Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Melanie C J Burgers
- Department of Pediatrics, Radboud Institute for Health Sciences, Radboud University Medical Center, Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Catelijne H Coppens
- Department of Pediatrics, Radboud Institute for Health Sciences, Radboud University Medical Center, Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Tuula Rinne
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Martin Zenker
- Institute of Human Genetics, University Hospital Magdeburg, Magdeburg, Germany
| | - Marco Tartaglia
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Wesley Reintjes
- Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Nicol C Voermans
- Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Baziel G M van Engelen
- Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Nens van Alfen
- Department of Neurology, Clinical Neuromuscular Imaging Group, Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Jos M T Draaisma
- Department of Pediatrics, Radboud Institute for Health Sciences, Radboud University Medical Center, Amalia Children's Hospital, Nijmegen, The Netherlands
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5
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Horn S, Neuhann T, Hennig C, Abad-Perez A, Prott EC, Cardellini L, Potratz C, Leubner J, Eichhorn B, Merkel M, Abicht A, Kaindl AM. LZTR1 loss-of-function variants associated with café au lait macules with or without freckling. Front Neurol 2024; 15:1391425. [PMID: 39258154 PMCID: PMC11383758 DOI: 10.3389/fneur.2024.1391425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Accepted: 08/05/2024] [Indexed: 09/12/2024] Open
Abstract
Pathogenic variants in the leucine zipper-like transcriptional regulator 1 gene (LZTR1) have been identified in schwannomatosis and Noonan syndrome. Here, we expand the phenotype spectrum of LZTR1 variants. We identified four loss-of-function heterozygous LZTR1 variants in five children with multiple café au lait macules and one adult with multiple café au lait macules and axillar freckling, by applying gene panel analysis in four families. The three LZTR1 variants, namely, c.184del/p.Glu62Serfs*39, c.1927C < T/p.Gln643*, and c.857_858delinsT/p.Gly286Valfs*65, were novel, whereas the variant c.1018C > T/ p.Arg340* had been previously reported in a patient with schwannomatosis. Similar to what is known from other LZTR1-associated conditions, penetrance of the skin manifestations was reduced in two carriers of the familial variants. Our study expands the LZTR1 phenotype to the presence of isolated café au lait macules with or without freckling. Thus, variants in the LZTR1 gene should be considered in patients with multiple café au lait macules.
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Affiliation(s)
- Svea Horn
- Charité-Universitätsmedizin Berlin, Department of Pediatric Neurology, Berlin, Germany
- Charité-Universitätsmedizin Berlin, Center for Chronically Sick Children, Berlin, Germany
| | | | - Corina Hennig
- Mitteldeutscher Praxisverbund Humangenetik, Dresden, Germany
| | - Angela Abad-Perez
- Charité-Universitätsmedizin Berlin, Institute of Human Genetics, Berlin, Germany
| | | | - Lisa Cardellini
- Charité-Universitätsmedizin Berlin, Department of Pediatric Neurology, Berlin, Germany
- Charité-Universitätsmedizin Berlin, Center for Chronically Sick Children, Berlin, Germany
| | - Cornelia Potratz
- Charité-Universitätsmedizin Berlin, Department of Pediatric Neurology, Berlin, Germany
- Charité-Universitätsmedizin Berlin, Center for Chronically Sick Children, Berlin, Germany
| | - Jonas Leubner
- Charité-Universitätsmedizin Berlin, Department of Pediatric Neurology, Berlin, Germany
- Charité-Universitätsmedizin Berlin, Center for Chronically Sick Children, Berlin, Germany
| | - Birgit Eichhorn
- Mitteldeutscher Praxisverbund Humangenetik, Dresden, Germany
| | - Martin Merkel
- Mitteldeutscher Praxisverbund Humangenetik, Dresden, Germany
| | - Angela Abicht
- MGZ - Medizinisch Genetisches Zentrum, München, Germany
| | - Angela M Kaindl
- Charité-Universitätsmedizin Berlin, Department of Pediatric Neurology, Berlin, Germany
- Charité-Universitätsmedizin Berlin, Center for Chronically Sick Children, Berlin, Germany
- Charité-Universitätsmedizin Berlin, Institute for Cell Biology and Neurobiology, Berlin, Germany
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6
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Uliana V, Ambrosini E, Taiani A, Cesarini S, Cannizzaro IR, Negrotti A, Serra W, Quintavalle G, Micale L, Fusco C, Castori M, Martorana D, Bortesi B, Belli L, Percesepe A, Pisani F, Barili V. Phenotypic Expansion of Autosomal Dominant LZTR1-Related Disorders with Special Emphasis on Adult-Onset Features. Genes (Basel) 2024; 15:916. [PMID: 39062695 PMCID: PMC11276570 DOI: 10.3390/genes15070916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 07/09/2024] [Accepted: 07/10/2024] [Indexed: 07/28/2024] Open
Abstract
Leucine zipper-like transcription regulator 1 (LZTR1) acts as a negative factor that suppresses RAS function and MAPK signaling; mutations in this protein may dysregulate RAS ubiquitination and lead to impaired degradation of RAS superfamily proteins. Germline LZTR1 variants are reported in Noonan syndrome, either autosomal dominant or autosomal recessive, and in susceptibility to schwannomatosis. This article explores the genetic and phenotypic diversity of the autosomal dominant LZTR1-related disorders, compiling a cohort of previously published patients (51 with the Noonan phenotype and 123 with schwannomatosis) and presenting two additional adult-onset cases: a male with schwannomatosis and Parkinson's disease and a female with Noonan syndrome, generalized joint hypermobility, and breast cancer. This review confirms that autosomal dominant LZTR1-related disorders exhibit an extreme phenotypic variability, ranging from relatively mild manifestations to severe and multi-systemic involvement, and offers updated frequences of each clinical feature. The aim is to precisely define the clinical spectrum of LZTR1-related diseases, using also two new emblematic clinical cases. Gaining insight into the mechanisms underneath this variability is crucial to achieve precision diagnostics and the development of therapeutic interventions.
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Affiliation(s)
- Vera Uliana
- Medical Genetics, University Hospital of Parma, 43126 Parma, Italy
| | - Enrico Ambrosini
- Medical Genetics, University Hospital of Parma, 43126 Parma, Italy
| | - Antonietta Taiani
- Medical Genetics, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy (D.M.)
| | - Sofia Cesarini
- Medical Genetics, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy (D.M.)
| | - Ilenia Rita Cannizzaro
- Medical Genetics, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy (D.M.)
| | - Anna Negrotti
- Neurology Unit, University Hospital of Parma, 43126 Parma, Italy
| | - Walter Serra
- Unit of Cardiology, University Hospital of Parma, 43126 Parma, Italy
| | - Gabriele Quintavalle
- Regional Reference Centre for Inherited Bleeding Disorders, University Hospital of Parma, 43126 Parma, Italy
| | - Lucia Micale
- Division of Medical Genetics, Fondazione IRCCS-Casa Sollievo della Sofferenza, Viale Cappuccini snc, San Giovanni Rotondo, 71013 Foggia, Italy
| | - Carmela Fusco
- Division of Medical Genetics, Fondazione IRCCS-Casa Sollievo della Sofferenza, Viale Cappuccini snc, San Giovanni Rotondo, 71013 Foggia, Italy
| | - Marco Castori
- Division of Medical Genetics, Fondazione IRCCS-Casa Sollievo della Sofferenza, Viale Cappuccini snc, San Giovanni Rotondo, 71013 Foggia, Italy
| | - Davide Martorana
- Medical Genetics, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy (D.M.)
| | - Beatrice Bortesi
- Medical Oncology Unit, University Hospital of Parma, 43126 Parma, Italy
| | - Laura Belli
- Neurosurgery Unit, Head and Neck Department, University Hospital of Parma, 43126 Parma, Italy
| | - Antonio Percesepe
- Medical Genetics, University Hospital of Parma, 43126 Parma, Italy
- Medical Genetics, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy (D.M.)
| | - Francesco Pisani
- Child Neurology and Psychiatry Unit, Department of Human Neuroscience, Sapienza University, Via dei Sabelli 108, 00185 Rome, Italy
| | - Valeria Barili
- Medical Genetics, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy (D.M.)
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7
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Knauer C, Haltern H, Schoger E, Kügler S, Roos L, Zelarayán LC, Hasenfuss G, Zimmermann WH, Wollnik B, Cyganek L. Preclinical evaluation of CRISPR-based therapies for Noonan syndrome caused by deep-intronic LZTR1 variants. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102123. [PMID: 38333672 PMCID: PMC10851011 DOI: 10.1016/j.omtn.2024.102123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 01/18/2024] [Indexed: 02/10/2024]
Abstract
Gene variants in LZTR1 are implicated to cause Noonan syndrome associated with a severe and early-onset hypertrophic cardiomyopathy. Mechanistically, LZTR1 deficiency results in accumulation of RAS GTPases and, as a consequence, in RAS-MAPK signaling hyperactivity, thereby causing the Noonan syndrome-associated phenotype. Despite its epidemiological relevance, pharmacological as well as invasive therapies remain limited. Here, personalized CRISPR-Cas9 gene therapies might offer a novel alternative for a curative treatment in this patient cohort. In this study, by utilizing a patient-specific screening platform based on iPSC-derived cardiomyocytes from two Noonan syndrome patients, we evaluated different clinically translatable therapeutic approaches using small Cas9 orthologs targeting a deep-intronic LZTR1 variant to cure the disease-associated molecular pathology. Despite high editing efficiencies in cardiomyocyte cultures transduced with lentivirus or all-in-one adeno-associated viruses, we observed crucial differences in editing outcomes in proliferative iPSCs vs. non-proliferative cardiomyocytes. While editing in iPSCs rescued the phenotype, the same editing approaches did not robustly restore LZTR1 function in cardiomyocytes, indicating critical differences in the activity of DNA double-strand break repair mechanisms between proliferative and non-proliferative cell types and highlighting the importance of cell type-specific screens for testing CRISPR-Cas9 gene therapies.
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Affiliation(s)
- Carolin Knauer
- Stem Cell Unit, Clinic for Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
| | - Henrike Haltern
- Stem Cell Unit, Clinic for Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
| | - Eric Schoger
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Sebastian Kügler
- Department of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Lennart Roos
- Stem Cell Unit, Clinic for Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany
| | - Laura C. Zelarayán
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, 37075 Göttingen, Germany
- Department of Cardiology and Angiology, University of Giessen, 35390 Giessen, Germany
| | - Gerd Hasenfuss
- Stem Cell Unit, Clinic for Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany
| | - Wolfram-Hubertus Zimmermann
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, 37075 Göttingen, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, 37075 Göttingen, Germany
- DZNE (German Center for Neurodegenerative Diseases), 37075 Göttingen, Germany
| | - Bernd Wollnik
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany
- Institute of Human Genetics, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Lukas Cyganek
- Stem Cell Unit, Clinic for Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, 37075 Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, 37075 Göttingen, Germany
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8
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Ayaz E, Yıldırım R, Çelebi C, Ozalkak S. Noonan syndrome: Neuroimaging findings and morphometric analysis of the cranium base and posterior fossa in children. J Neuroimaging 2023; 33:318-327. [PMID: 36480458 DOI: 10.1111/jon.13075] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 10/28/2022] [Accepted: 11/23/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND AND PURPOSE There are a few studies regarding intracranial findings in neonates with Noonan syndrome (NS); however, there are no quantitative analyses in a pediatric population. The aim of this study was to find characteristic intracranial abnormalities and to quantitatively analyze the posterior fossa and cranium base in children with NS. METHODS A total of 30 patients (11 females and 19 males, mean age 13.1 ± 4.3 years) were retrospectively identified between July 2017 and June 2022. Twenty-one patients had MRI. Age at MRI examination, sex, genetic mutations, and clinical findings were noted. In patients with MRI, the presence of white matter lesions, basal ganglia lesions, corpus callosum abnormalities, sellar/parasellar lesions, and tonsillar ectopia was noted. For morphometric analysis, cerebellar diameter, vermis and clivus heights, cranial base, tentorial and infratentorial angles, and McRae's and Twining's lines were each measured twice by two radiologists individually. RESULTS The most common lesions were focal white matter lesions, followed by abnormalities of the splenium of the corpus callosum. The cerebellar diameter, vermis and clivus heights, Twining's line, and infratentorial angle were significantly smaller; cranial base angle and tentorial angle were significantly larger in NS (p < .05). Interrater and intrarater agreements were the highest for cerebellar diameter and the lowest for tentorial angle measurements. CONCLUSION Children with NS had characteristic callosal and tentorial findings and neuroimaging findings similar to other RASopathies. This study also shows that a small posterior fossa and flattening of the cranial base are present in children with NS, which may aid in diagnosis.
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Affiliation(s)
- Ercan Ayaz
- Department of Radiology, Diyarbakir Children's Hospital, Diyarbakir, Turkey
| | - Ruken Yıldırım
- Department of Pediatric Endocrinology, Diyarbakir Children's Hospital, Diyarbakir, Turkey
| | - Canan Çelebi
- Department of Radiology, Diyarbakir Children's Hospital, Diyarbakir, Turkey
| | - Servan Ozalkak
- Department of Pediatric Endocrinology, Diyarbakir Children's Hospital, Diyarbakir, Turkey
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Priolo M, Mancini C, Radio FC, Chiriatti L, Ciolfi A, Cappelletti C, Cordeddu V, Pintomalli L, Brusco A, Mammi C, Tartaglia M. Natural history of MRAS-related Noonan syndrome: Evidence of mild adult-onset left ventricular hypertrophy and neuropsychiatric features. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2023. [PMID: 36734411 DOI: 10.1002/ajmg.c.32034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 01/23/2023] [Indexed: 02/04/2023]
Abstract
Gain of function pathogenic variants in MRAS have been found in a small subset of pediatric subjects presenting with Noonan syndrome (NS) associated with hypertrophic cardiomyopathy (HCM) and moderate to severe intellectual disability. These variants are considered to confer a high-risk for the development of severe HCM with poor prognosis and fatal outcome. We report on the natural history of the first adult subject with NS carrying the recurrent pathogenic p.Thr68Ile amino acid substitution. Different from what had previously been observed, he presented with a mild, late-onset left ventricular hypertrophy, and a constellation of additional symptoms rarely seen in NS. The present case provides evidence that HCM does not represent an obligatory, early-onset and severe complication in subjects with MRAS variants. It also adds new data about late-onset features suggesting that other unexpected complications might be observed in adult subjects providing anticipatory guidance for individuals of all age.
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Affiliation(s)
- Manuela Priolo
- USD Genetica Medica, Grande Ospedale Metropolitano Bianchi-Melacrino-Morelli, Reggio Calabria, Italy
| | - Cecilia Mancini
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | | | - Luigi Chiriatti
- USD Genetica Medica, Grande Ospedale Metropolitano Bianchi-Melacrino-Morelli, Reggio Calabria, Italy
| | - Andrea Ciolfi
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Camilla Cappelletti
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Viviana Cordeddu
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Letizia Pintomalli
- USD Genetica Medica, Grande Ospedale Metropolitano Bianchi-Melacrino-Morelli, Reggio Calabria, Italy
| | - Alfredo Brusco
- Department of Medical Sciences, University of Torino, Turin, Italy
| | - Corrado Mammi
- USD Genetica Medica, Grande Ospedale Metropolitano Bianchi-Melacrino-Morelli, Reggio Calabria, Italy
| | - Marco Tartaglia
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
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Tartaglia M, Aoki Y, Gelb BD. The molecular genetics of RASopathies: An update on novel disease genes and new disorders. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2022; 190:425-439. [PMID: 36394128 PMCID: PMC10100036 DOI: 10.1002/ajmg.c.32012] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 10/31/2022] [Accepted: 11/05/2022] [Indexed: 11/18/2022]
Abstract
Enhanced signaling through RAS and the mitogen-associated protein kinase (MAPK) cascade underlies the RASopathies, a family of clinically related disorders affecting development and growth. In RASopathies, increased RAS-MAPK signaling can result from the upregulated activity of various RAS GTPases, enhanced function of proteins positively controlling RAS function or favoring the efficient transmission of RAS signaling to downstream transducers, functional upregulation of RAS effectors belonging to the MAPK cascade, or inefficient signaling switch-off operated by feedback mechanisms acting at different levels. The massive effort in RASopathy gene discovery performed in the last 20 years has identified more than 20 genes implicated in these disorders. It has also facilitated the characterization of several molecular activating mechanisms that had remained unappreciated due to their minor impact in oncogenesis. Here, we provide an overview on the discoveries collected during the last 5 years that have delivered unexpected insights (e.g., Noonan syndrome as a recessive disease) and allowed to profile new RASopathies, novel disease genes and new molecular circuits contributing to the control of RAS-MAPK signaling.
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Affiliation(s)
- Marco Tartaglia
- Genetics and Rare Diseases Research DivisionOspedale Pediatrico Bambino Gesù, IRCCSRomeItaly
| | - Yoko Aoki
- Department of Medical GeneticsTohoku University School of MedicineSendaiJapan
| | - Bruce D. Gelb
- Mindich Child Health and Development InstituteIcahn School of Medicine at Mount SinaiNew YorkNew YorkUSA
- Department of Pediatrics and GeneticsIcahn School of Medicine at Mount SinaiNew YorkNew YorkUSA
- Department of Genomic SciencesIcahn School of Medicine at Mount SinaiNew YorkNew YorkUSA
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