{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,17]],"date-time":"2026-06-17T22:53:08Z","timestamp":1781736788919,"version":"3.54.5"},"reference-count":48,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2026,4,23]],"date-time":"2026-04-23T00:00:00Z","timestamp":1776902400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,6,18]],"date-time":"2026-06-18T00:00:00Z","timestamp":1781740800000},"content-version":"vor","delay-in-days":56,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/501100003196","name":"Ministero della Salute","doi-asserted-by":"publisher","award":["GR-2019-12371203"],"award-info":[{"award-number":["GR-2019-12371203"]}],"id":[{"id":"10.13039\/501100003196","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Orphanet J Rare Dis"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>\n                      Costello syndrome (CS) is a rare genetic disorder within the spectrum of RASopathies, caused by activating mutations in the\n                      <jats:italic>HRAS<\/jats:italic>\n                      gene, leading to constitutive dysregulation of the RAS\/MAPK signalling pathway. Among its multisystemic manifestations, a distinctive musculoskeletal involvement is frequently observed with reduction in muscle force, pain of musculoskeletal origin and muscular hypotrophy. Moreover, abnormal histological findings with variability in size, atrophy, and prevalence of type 2-fibers have been detected on anecdotal muscular biopsies of affected individuals.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      We conducted a monocentric study on 20 individuals (13 females, 7 males; median age 19 years) with molecularly confirmed CS diagnosis, recruited between December 2019 and December 2022. Muscle ultrasonography (US) was performed to study muscle architecture and detect fibroadipose infiltration (FAI), a key determinant of muscle quality and functional performance on lumbar paravertebral, quadriceps (vastus medialis, vastus lateralis, rectus femoris), and gastrocnemius muscles. FAI was graded according to the Heckmatt scale (I\u2013IV). Nutritional and metabolic assessments were conducted including macronutrient intake (3 days diet recall) and resting energy expenditure (REE). To investigate the pathogenic contribution of HRAS dysregulation to skeletal muscle development, preclinical studies were performed in engineered mouse myoblasts expressing\n                      <jats:italic>HRAS<\/jats:italic>\n                      p.Gly12Ser and p.Gly13Cys variants.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>FAI was detected in 100% of participants in at least one muscle, most commonly in lumbar paravertebral muscles (85%) and vastus lateralis (70\u201375%); no grade IV involution cases occurred. FAI severity showed no association with age, physical activity, nutritional\/biochemical parameters, or REE, but displayed district\u2011specific correlations with skeletal anomalies (tight Achilles tendon and coxa valga). In vitro, myoblasts expressing HRAS mutants exhibited increased proliferation, impaired myogenic differentiation\/fusion, and lipid droplet accumulation with elevated cholesteryl esters compared with controls.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>US shows potential as a non-invasive tool for assessing and monitoring muscular health in CS and related RASopathies, though further data are needed to support its use. The pattern supports HRAS\u2011mediated metabolic dysfunction as a primary driver of FAI, warranting multicenter longitudinal studies with standardized quantitative metrics integrated with functional testing in the view of future therapeutic trials.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1186\/s13023-026-04332-3","type":"journal-article","created":{"date-parts":[[2026,4,23]],"date-time":"2026-04-23T07:14:33Z","timestamp":1776928473000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Muscle ultrasonography in costello syndrome: unveiling new clinical insights of a complex muscular phenotype"],"prefix":"10.1186","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4089-637X","authenticated-orcid":false,"given":"Chiara","family":"Leoni","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Germana","family":"Viscogliosi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Deborah","family":"Pajalunga","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Valentina","family":"Trevisan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ludovica","family":"Mondelli","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maria Luigia","family":"Angeli","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Consolato","family":"Gull\u00ec","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Massimo","family":"Tatti","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lucrezia","family":"Perri","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Iacopo","family":"Bellani","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicol\u00f2","family":"Lentini","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Roberta","family":"Pastorino","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eliza","family":"Kuczynska","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jacopo","family":"Gervasoni","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Domenico Marco Maurizio","family":"Romeo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marika","family":"Pane","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eugenio Maria","family":"Mercuri","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Serena","family":"Cecchetti","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giovanna","family":"Carpentieri","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marco","family":"Tartaglia","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giuseppe","family":"Zampino","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elisabetta","family":"Flex","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,4,23]]},"reference":[{"issue":"2","key":"4332_CR1","doi-asserted-by":"publisher","first-page":"dmm049107","DOI":"10.1242\/dmm.049107","volume":"15","author":"KE Hebron","year":"2022","unstructured":"Hebron KE, Hernandez ER, Yohe ME. The RASopathies: from pathogenetics to therapeutics. Dis Model Mech. 2022;15(2):dmm049107. https:\/\/doi.org\/10.1242\/dmm.049107. PubMed PMID: 35178568; PubMed Central PMCID: PMC8862741.","journal-title":"Dis Model Mech"},{"issue":"10","key":"4332_CR2","doi-asserted-by":"publisher","first-page":"1038","DOI":"10.1038\/ng1641","volume":"37","author":"Y Aoki","year":"2005","unstructured":"Aoki Y, Niihori T, Kawame H, Kurosawa K, Ohashi H, Tanaka Y, et al. Germline mutations in HRAS proto-oncogene cause Costello syndrome. Nat Genet. 2005;37(10):1038\u201340. https:\/\/doi.org\/10.1038\/ng1641.","journal-title":"Nat Genet"},{"key":"4332_CR3","doi-asserted-by":"publisher","first-page":"1277","DOI":"10.2147\/JMDH.S291757","volume":"15","author":"C Leoni","year":"2022","unstructured":"Leoni C, Viscogliosi G, Tartaglia M, Aoki Y, Zampino G. Multidisciplinary Management of Costello Syndrome: Current Perspectives. JMDH. 2022;15:1277\u201396. https:\/\/doi.org\/10.2147\/JMDH.S291757.","journal-title":"JMDH"},{"key":"4332_CR4","doi-asserted-by":"publisher","unstructured":"Leoni C, Viscogliosi G, Stevenson DA. Orthopedic issues of the RASopathies. In: Rauen KA, editor. The RASopathies [Internet]. Cham: Springer Nature Switzerland; 2024 [cited 2026 Jan 22]. pp. 795\u2013817. Available from: https:\/\/link.springer.com\/https:\/\/doi.org\/10.1007\/978-3-031-62945-7_36.","DOI":"10.1007\/978-3-031-62945-7_36"},{"issue":"9","key":"4332_CR5","doi-asserted-by":"publisher","first-page":"1725","DOI":"10.1002\/ajmg.a.61270","volume":"179","author":"KW Gripp","year":"2019","unstructured":"Gripp KW, Morse LA, Axelrad M, Chatfield KC, Chidekel A, Dobyns W, et al. Costello syndrome: Clinical phenotype, genotype, and management guidelines. Am J Med Genet Pt A. 2019;179(9):1725\u201344. https:\/\/doi.org\/10.1002\/ajmg.a.61270.","journal-title":"Am J Med Genet Pt A"},{"issue":"1","key":"4332_CR6","doi-asserted-by":"publisher","first-page":"40","DOI":"10.1002\/ajmg.a.36828","volume":"167","author":"B Johnson","year":"2015","unstructured":"Johnson B, Goldberg-Strassler D, Gripp K, Thacker M, Leoni C, Stevenson D. Function and disability in children with Costello syndrome and Cardiofaciocutaneous syndrome. Am J Med Genet Pt A. 2015;167(1):40\u20134. https:\/\/doi.org\/10.1002\/ajmg.a.36828.","journal-title":"Am J Med Genet Pt A"},{"issue":"6","key":"4332_CR7","doi-asserted-by":"publisher","first-page":"940","DOI":"10.1002\/ajmg.a.61111","volume":"179","author":"C Leoni","year":"2019","unstructured":"Leoni C, Triumbari EKA, Vollono C, Onesimo R, Podagrosi M, Giorgio V, et al. Pain in individuals with RASopathies: Prevalence and clinical characterization in a sample of 80 affected patients. Am J Med Genet Pt A. 2019;179(6):940\u20137. https:\/\/doi.org\/10.1002\/ajmg.a.61111.","journal-title":"Am J Med Genet Pt A"},{"issue":"1","key":"4332_CR8","doi-asserted-by":"publisher","first-page":"43","DOI":"10.1186\/s13023-021-01674-y","volume":"16","author":"C Leoni","year":"2021","unstructured":"Leoni C, Romeo DM, Pelliccioni M, Di Gi\u00e0 M, Onesimo R, Giorgio V, et al. Musculo-skeletal phenotype of Costello syndrome and cardio-facio-cutaneous syndrome: insights on the functional assessment status. Orphanet J Rare Dis. 2021;16(1):43. https:\/\/doi.org\/10.1186\/s13023-021-01674-y.","journal-title":"Orphanet J Rare Dis"},{"issue":"1","key":"4332_CR9","doi-asserted-by":"publisher","first-page":"84","DOI":"10.1002\/ajmg.a.33147","volume":"152A","author":"E Hopkins","year":"2010","unstructured":"Hopkins E, Lin AE, Krepkovich KE, Axelrad ME, Sol-Church K, Stabley DL, et al. Living with Costello syndrome: Quality of life issues in older individuals. Am J Med Genet Pt A. 2010;152A(1):84\u201390. https:\/\/doi.org\/10.1002\/ajmg.a.33147.","journal-title":"Am J Med Genet Pt A"},{"issue":"3","key":"4332_CR10","doi-asserted-by":"publisher","first-page":"394","DOI":"10.1002\/mus.23324","volume":"46","author":"DA Stevenson","year":"2012","unstructured":"Stevenson DA, Allen S, Tidyman WE, Carey JC, Viskochil DH, Stevens A, et al. Peripheral muscle weakness in RASopathies. Muscle Nerve. 2012;46(3):394\u20139. https:\/\/doi.org\/10.1002\/mus.23324.","journal-title":"Muscle Nerve"},{"issue":"2","key":"4332_CR11","doi-asserted-by":"publisher","first-page":"104","DOI":"10.1002\/ajmg.c.30298","volume":"157","author":"WE Tidyman","year":"2011","unstructured":"Tidyman WE, Lee HS, Rauen KA. Skeletal muscle pathology in Costello and cardio-facio\u2010cutaneous syndromes: Developmental consequences of germline Ras\/MAPK activation on myogenesis. Am J Med Genet Pt C. 2011;157(2):104\u201314. https:\/\/doi.org\/10.1002\/ajmg.c.30298.","journal-title":"Am J Med Genet Pt C"},{"issue":"8","key":"4332_CR12","doi-asserted-by":"publisher","first-page":"1074","DOI":"10.1002\/dvdy.309","volume":"250","author":"Y Maeda","year":"2021","unstructured":"Maeda Y, Tidyman WE, Ander BP, Pritchard CA, Rauen KA. Ras\/ MAPK dysregulation in development causes a skeletal myopathy in an activating Braf L597V mouse model for cardio-facio\u2010cutaneous syndrome. Dev Dyn. 2021;250(8):1074\u201395. https:\/\/doi.org\/10.1002\/dvdy.309.","journal-title":"Dev Dyn"},{"key":"4332_CR13","doi-asserted-by":"publisher","DOI":"10.1242\/dmm.049166","author":"WE Tidyman","year":"2021","unstructured":"Tidyman WE, Goodwin AF, Maeda Y, Klein OD, Rauen KA. MEK-inhibitor-mediated rescue of skeletal myopathy caused by activating Hras mutation in a Costello syndrome mouse model. Dis Models Mech. 2021. https:\/\/doi.org\/10.1242\/dmm.049166. dmm.049166.","journal-title":"Dis Models Mech"},{"issue":"6","key":"4332_CR14","doi-asserted-by":"publisher","first-page":"dmm050609","DOI":"10.1242\/dmm.050609","volume":"17","author":"KA Rauen","year":"2024","unstructured":"Rauen KA, Tidyman WE. RASopathies \u2013 what they reveal about RAS\/MAPK signaling in skeletal muscle development. Dis Models Mech. 2024;17(6):dmm050609. https:\/\/doi.org\/10.1242\/dmm.050609.","journal-title":"Dis Models Mech"},{"key":"4332_CR15","doi-asserted-by":"publisher","first-page":"91","DOI":"10.1016\/j.jot.2018.10.004","volume":"15","author":"K Engelke","year":"2018","unstructured":"Engelke K, Museyko O, Wang L, Laredo JD. Quantitative analysis of skeletal muscle by computed tomography imaging\u2014State of the art. J Orthop Translation. 2018;15:91\u2013103. https:\/\/doi.org\/10.1016\/j.jot.2018.10.004.","journal-title":"J Orthop Translation"},{"issue":"8","key":"4332_CR16","doi-asserted-by":"publisher","first-page":"1436","DOI":"10.3390\/diagnostics13081436","volume":"13","author":"C Pirri","year":"2023","unstructured":"Pirri C, Pirri N, Guidolin D, Macchi V, Porzionato A, De Caro R, et al. Ultrasound Imaging of Thoracolumbar Fascia Thickness: Chronic Non-Specific Lower Back Pain versus Healthy Subjects; A Sign of a Frozen Back? Diagnostics. 2023;13(8):1436. https:\/\/doi.org\/10.3390\/diagnostics13081436.","journal-title":"Diagnostics"},{"key":"4332_CR17","doi-asserted-by":"publisher","first-page":"38","DOI":"10.1016\/j.yclnex.2020.06.003","volume":"32","author":"A Fischer","year":"2020","unstructured":"Fischer A, Anwar M, Hertwig A, Hahn R, Pesta M, Timmermann I, et al. Ultrasound method of the USVALID study to measure subcutaneous adipose tissue and muscle thickness on the thigh and upper arm: An illustrated step-by-step guide. Clin Nutr Experimental. 2020;32:38\u201373. https:\/\/doi.org\/10.1016\/j.yclnex.2020.06.003.","journal-title":"Clin Nutr Experimental"},{"issue":"6","key":"4332_CR18","doi-asserted-by":"publisher","first-page":"679","DOI":"10.1002\/mus.21015","volume":"37","author":"S Pillen","year":"2008","unstructured":"Pillen S, Arts IMP, Zwarts MJ. Muscle ultrasound in neuromuscular disorders. Muscle Nerve. 2008;37(6):679\u201393. https:\/\/doi.org\/10.1002\/mus.21015.","journal-title":"Muscle Nerve"},{"issue":"10","key":"4332_CR19","doi-asserted-by":"publisher","first-page":"1016","DOI":"10.1179\/1743132811Y.0000000010","volume":"33","author":"S Pillen","year":"2011","unstructured":"Pillen S, Van Alfen N. Skeletal muscle ultrasound. Neurol Res. 2011;33(10):1016\u201324. https:\/\/doi.org\/10.1179\/1743132811Y.0000000010.","journal-title":"Neurol Res"},{"key":"4332_CR20","doi-asserted-by":"publisher","first-page":"843","DOI":"10.1016\/B978-0-444-53486-6.00042-9","volume":"136","author":"S Pillen","year":"2016","unstructured":"Pillen S, Boon A, Van Alfen N. Muscle ultrasound. Handb Clin Neurol. 2016;136:843\u201353. https:\/\/doi.org\/10.1016\/B978-0-444-53486-6.00042-9. PubMed PMID: 27430445.","journal-title":"Handb Clin Neurol"},{"issue":"2","key":"4332_CR21","doi-asserted-by":"publisher","first-page":"168","DOI":"10.2478\/raon-2023-0025","volume":"57","author":"M Petric","year":"2023","unstructured":"Petric M, Jordan T, Karteek P, Licen S, Trotovsek B, Tomazic A. Radiological assessment of skeletal muscle index and myosteatosis and their impact postoperative outcomes after liver transplantation. Radiol Oncol. 2023;57(2):168\u201377. https:\/\/doi.org\/10.2478\/raon-2023-0025.","journal-title":"Radiol Oncol"},{"issue":"10","key":"4332_CR22","doi-asserted-by":"publisher","first-page":"afac220","DOI":"10.1093\/ageing\/afac220","volume":"51","author":"AA Sayer","year":"2022","unstructured":"Sayer AA, Cruz-Jentoft A. Sarcopenia definition, diagnosis and treatment: consensus is growing. Age Ageing. 2022;51(10):afac220. https:\/\/doi.org\/10.1093\/ageing\/afac220.","journal-title":"Age Ageing"},{"issue":"2","key":"4332_CR23","doi-asserted-by":"publisher","first-page":"100963","DOI":"10.1016\/j.jhepr.2023.100963","volume":"6","author":"G Henin","year":"2024","unstructured":"Henin G, Loumaye A, Leclercq IA, Lanthier N, Myosteatosis. Diagnosis, pathophysiology and consequences in metabolic dysfunction-associated steatotic liver disease. JHEP Rep. 2024;6(2):100963. https:\/\/doi.org\/10.1016\/j.jhepr.2023.100963.","journal-title":"JHEP Rep"},{"issue":"4","key":"4332_CR24","doi-asserted-by":"publisher","first-page":"540","DOI":"10.1002\/mus.24564","volume":"52","author":"GEA Habers","year":"2015","unstructured":"Habers GEA, Van Brussel M, Bhansing KJ, Hoppenreijs EP, Janssen AJWM, Van Royen-Kerkhof A, et al. Quantitative muscle ultrasonography in the follow\u2010up of juvenile dermatomyositis. Muscle Nerve. 2015;52(4):540\u20136. https:\/\/doi.org\/10.1002\/mus.24564.","journal-title":"Muscle Nerve"},{"issue":"7","key":"4332_CR25","doi-asserted-by":"publisher","first-page":"3449","DOI":"10.1007\/s10072-024-07340-y","volume":"45","author":"SY Tan","year":"2024","unstructured":"Tan SY, Tan CY, Yahya MA, Low SC, Shahrizaila N, Goh KJ. Quantitative muscle ultrasound as a disease biomarker in hereditary transthyretin amyloidosis with polyneuropathy. Neurol Sci. 2024;45(7):3449\u201359. https:\/\/doi.org\/10.1007\/s10072-024-07340-y.","journal-title":"Neurol Sci"},{"issue":"2","key":"4332_CR26","doi-asserted-by":"publisher","first-page":"80","DOI":"10.1097\/WNP.0000000000000234","volume":"33","author":"HD Katzberg","year":"2016","unstructured":"Katzberg HD, Bril V, Breiner A. Ultrasound in Neuromuscular Disorders. J Clin Neurophysiol. 2016;33(2):80\u20135. https:\/\/doi.org\/10.1097\/WNP.0000000000000234.","journal-title":"J Clin Neurophysiol"},{"issue":"3","key":"4332_CR27","doi-asserted-by":"publisher","first-page":"253","DOI":"10.1002\/mus.27669","volume":"66","author":"J Wijntjes","year":"2022","unstructured":"Wijntjes J, Van Der Hoeven J, Saris CGJ, Doorduin J, Van Alfen N. Visual versus quantitative analysis of muscle ultrasound in neuromuscular disease. Muscle Nerve. 2022;66(3):253\u201361. https:\/\/doi.org\/10.1002\/mus.27669.","journal-title":"Muscle Nerve"},{"issue":"12","key":"4332_CR28","doi-asserted-by":"publisher","first-page":"936","DOI":"10.1016\/j.nmd.2023.10.015","volume":"33","author":"SCC Vincenten","year":"2023","unstructured":"Vincenten SCC, Teeselink S, Voermans NC, Van Engelen BGM, Mul K, Van Alfen N. Establishing the role of muscle ultrasound as an imaging biomarker in facioscapulohumeral muscular dystrophy. Neuromuscul Disord. 2023;33(12):936\u201344. https:\/\/doi.org\/10.1016\/j.nmd.2023.10.015.","journal-title":"Neuromuscul Disord"},{"issue":"4","key":"4332_CR29","doi-asserted-by":"publisher","first-page":"100071","DOI":"10.1016\/j.arrct.2020.100071","volume":"2","author":"MC Moreta","year":"2020","unstructured":"Moreta MC, Fleet A, Reebye R, McKernan G, Berger M, Farag J, et al. Reliability and Validity of the Modified Heckmatt Scale in Evaluating Muscle Changes With Ultrasound in Spasticity. Archives Rehabilitation Res Clin Translation. 2020;2(4):100071. https:\/\/doi.org\/10.1016\/j.arrct.2020.100071.","journal-title":"Archives Rehabilitation Res Clin Translation"},{"issue":"9","key":"4332_CR30","doi-asserted-by":"publisher","first-page":"754","DOI":"10.1016\/j.nmd.2022.05.004","volume":"32","author":"R Harada","year":"2022","unstructured":"Harada R, Taniguchi-Ikeda M, Nagasaka M, Nishii T, Inui A, Yamamoto T, et al. Assessment of the upper limb muscles in patients with Fukuyama muscular dystrophy: Noninvasive assessment using visual ultrasound muscle analysis and shear wave elastography. Neuromuscul Disord. 2022;32(9):754\u201362. https:\/\/doi.org\/10.1016\/j.nmd.2022.05.004.","journal-title":"Neuromuscul Disord"},{"issue":"2","key":"4332_CR31","doi-asserted-by":"publisher","first-page":"215","DOI":"10.1016\/S0301-5629(02)00758-5","volume":"29","author":"NM Maurits","year":"2003","unstructured":"Maurits NM, Bollen AE, Windhausen A, De Jager AEJ, Van Der Hoeven JH. Muscle ultrasound analysis: normal values and differentiation between myopathies and neuropathies. Ultrasound Med Biol. 2003;29(2):215\u201325. https:\/\/doi.org\/10.1016\/S0301-5629(02)00758-5.","journal-title":"Ultrasound Med Biol"},{"issue":"6","key":"4332_CR32","doi-asserted-by":"publisher","first-page":"1247","DOI":"10.3390\/nu11061247","volume":"11","author":"A Mateos-Angulo","year":"2019","unstructured":"Mateos-Angulo A, Gal\u00e1n-Mercant A, Cuesta-Vargas AI. Ultrasound Muscle Assessment and Nutritional Status in Institutionalized Older Adults: A Pilot Study. Nutrients. 2019;11(6):1247. https:\/\/doi.org\/10.3390\/nu11061247 PubMed PMID: 31159255; PubMed Central PMCID: PMC6627854.","journal-title":"Nutrients"},{"issue":"6","key":"4332_CR33","doi-asserted-by":"publisher","first-page":"693","DOI":"10.1002\/mus.10384","volume":"27","author":"RR Scholten","year":"2003","unstructured":"Scholten RR, Pillen S, Verrips A, Zwarts MJ. Quantitative ultrasonography of skeletal muscles in children: normal values. Muscle Nerve. 2003;27(6):693\u20138. https:\/\/doi.org\/10.1002\/mus.10384. PubMed PMID: 12766980.","journal-title":"Muscle Nerve"},{"issue":"5","key":"4332_CR34","doi-asserted-by":"publisher","first-page":"656","DOI":"10.1016\/S0022-3476(82)80286-2","volume":"101","author":"JZ Heckmatt","year":"1982","unstructured":"Heckmatt JZ, Leeman S, Dubowitz V. Ultrasound imaging in the diagnosis of muscle disease. J Pediatr. 1982;101(5):656\u201360. https:\/\/doi.org\/10.1016\/S0022-3476(82)80286-2.","journal-title":"J Pediatr"},{"key":"4332_CR35","volume-title":"LARN\u2014Livelli di Assunzione di Riferimento di Nutrienti ed Energia per la popolazione Italiana. IV revisione","author":"Societ\u00e0 Italiana di Nutrizione Umana (SINU)","year":"2014","unstructured":"Societ\u00e0 Italiana di Nutrizione Umana (SINU). LARN\u2014Livelli di Assunzione di Riferimento di Nutrienti ed Energia per la popolazione Italiana. IV revisione. Milano: SICS; 2014."},{"issue":"Suppl 1","key":"4332_CR36","first-page":"5","volume":"39","author":"WN Schofield","year":"1985","unstructured":"Schofield WN. Predicting basal metabolic rate, new standards and review of previous work. Hum Nutr Clin Nutr. 1985;39(Suppl 1):5\u201341. PubMed PMID: 4044297.","journal-title":"Hum Nutr Clin Nutr"},{"issue":"3","key":"4332_CR37","doi-asserted-by":"publisher","first-page":"763","DOI":"10.1083\/jcb.95.3.763","volume":"95","author":"D Bader","year":"1982","unstructured":"Bader D, Masaki T, Fischman DA. Immunochemical analysis of myosin heavy chain during avian myogenesis in vivo and in vitro. J Cell Biol. 1982;95(3):763\u201370. https:\/\/doi.org\/10.1083\/jcb.95.3.763.","journal-title":"J Cell Biol"},{"issue":"Pt 18","key":"4332_CR38","doi-asserted-by":"publisher","first-page":"3677","DOI":"10.1242\/jcs.00735","volume":"116","author":"C Prigent","year":"2003","unstructured":"Prigent C, Dimitrov S. Phosphorylation of serine 10 in histone H3, what for? J Cell Sci. 2003;116(Pt 18):3677\u201385. https:\/\/doi.org\/10.1242\/jcs.00735. PubMed PMID: 12917355.","journal-title":"J Cell Sci"},{"issue":"4","key":"4332_CR39","doi-asserted-by":"publisher","first-page":"561","DOI":"10.1093\/hmg\/ddab","volume":"31","author":"G Carpentieri","year":"2022","unstructured":"Carpentieri G, Leoni C, Pietraforte D, Cecchetti S, Iorio E, Belardo A, et al. Hyperactive HRAS dysregulates energetic metabolism in fibroblasts from patients with Costello syndrome via enhanced production of reactive oxidizing species. Hum Mol Genet. 2022;31(4):561\u201375. https:\/\/doi.org\/10.1093\/hmg\/ddab. 270 PubMed PMID: 34508588.","journal-title":"Hum Mol Genet"},{"key":"4332_CR40","doi-asserted-by":"publisher","first-page":"116539","DOI":"10.1016\/j.bone.2022.116539","volume":"164","author":"A Al Saedi","year":"2022","unstructured":"Al Saedi A, Debruin DA, Hayes A, Hamrick M. Lipid metabolism in sarcopenia. Bone. 2022;164:116539. https:\/\/doi.org\/10.1016\/j.bone.2022.116539.","journal-title":"Bone"},{"issue":"7","key":"4332_CR41","doi-asserted-by":"publisher","first-page":"645","DOI":"10.1016\/j.tem.2024.10.006","volume":"36","author":"J Chen","year":"2025","unstructured":"Chen J, Markworth JF, Ferreira C, Zhang C, Kuang S. Lipid droplets as cell fate determinants in skeletal muscle. Trends Endocrinol Metabolism. 2025;36(7):645\u201359. https:\/\/doi.org\/10.1016\/j.tem.2024.10.006.","journal-title":"Trends Endocrinol Metabolism"},{"issue":"3","key":"4332_CR42","doi-asserted-by":"publisher","first-page":"230","DOI":"10.1016\/j.gde","volume":"19","author":"WE Tidyman","year":"2009","unstructured":"Tidyman WE, Rauen KA. The RASopathies: developmental syndromes of Ras\/MAPK pathway dysregulation. Curr Opin Genet Dev. 2009;19(3):230\u20136. https:\/\/doi.org\/10.1016\/j.gde. 2009.04.001 PubMed PMID: 19467855; PubMed Central PMCID: PMC2743116.","journal-title":"Curr Opin Genet Dev"},{"issue":"1","key":"4332_CR43","doi-asserted-by":"publisher","first-page":"41","DOI":"10.1016\/j.ymgme.2013.08.007","volume":"111","author":"C Leoni","year":"2014","unstructured":"Leoni C, Stevenson DA, Martini L, De Sanctis R, Mascolo G, Pantaleoni F, et al. Decreased bone mineral density in Costello syndrome. Mol Genet Metab. 2014;111(1):41\u20135. https:\/\/doi.org\/10.1016\/j.ymgme.2013.08.007.","journal-title":"Mol Genet Metab"},{"issue":"2","key":"4332_CR44","doi-asserted-by":"publisher","first-page":"422","DOI":"10.1002\/ajmg.a.62615","volume":"188","author":"C Leoni","year":"2022","unstructured":"Leoni C, Bisanti C, Viscogliosi G, Onesimo R, Massese M, Giorgio V, et al. Bone tissue homeostasis and risk of fractures in Costello syndrome: A 4-year follow-up study. Am J Med Genet A. 2022;188(2):422\u201330. https:\/\/doi.org\/10.1002\/ajmg.a.62615. PubMed PMID: 34913244.","journal-title":"Am J Med Genet A"},{"key":"4332_CR45","doi-asserted-by":"publisher","first-page":"116170","DOI":"10.1016\/j.bone.2021.116170","volume":"153","author":"M Delagrange","year":"2021","unstructured":"Delagrange M, Rousseau V, Cessans C, Pienkowski C, Oliver I, Jouret B, et al. Low bone mass in Noonan syndrome children correlates with decreased muscle mass and low IGF-1 levels. Bone. 2021;153:116170. https:\/\/doi.org\/10.1016\/j.bone.2021.116170.","journal-title":"Bone"},{"issue":"14","key":"4332_CR46","doi-asserted-by":"publisher","first-page":"2697","DOI":"10.1093\/hmg\/ddr149","volume":"20","author":"N Kossler","year":"2011","unstructured":"Kossler N, Stricker S, R\u00f6delsperger C, Robinson PN, Kim J, Dietrich C, et al. Neurofibromin (Nf1) is required for skeletal muscle development. Hum Mol Genet. 2011;20(14):2697\u2013709. https:\/\/doi.org\/10.1093\/hmg\/ddr149. PubMed PMID: 21478499; PubMed Central PMCID: PMC3118757.","journal-title":"Hum Mol Genet"},{"issue":"1","key":"4332_CR47","doi-asserted-by":"publisher","first-page":"25","DOI":"10.1111\/joim.12071","volume":"274","author":"J Bor\u00e9n","year":"2013","unstructured":"Bor\u00e9n J, Taskinen MR, Olofsson SO, Levin M. Ectopic lipid storage and insulin resistance: a harmful relationship. J Intern Med. 2013;274(1):25\u201340. https:\/\/doi.org\/10.1111\/joim.12071. PubMed PMID: 23551521.","journal-title":"J Intern Med"},{"issue":"4","key":"4332_CR48","doi-asserted-by":"publisher","first-page":"e70000","DOI":"10.1002\/jcsm.70000","volume":"16","author":"SY Jang","year":"2025","unstructured":"Jang SY, Choi KM. Impact of Adipose Tissue and Lipids on Skeletal Muscle in Sarcopenia. J Cachexia Sarcopenia Muscle. 2025;16(4):e70000. https:\/\/doi.org\/10.1002\/jcsm.70000. PubMed PMID: 40641114; PubMed Central PMCID: PMC12246390.","journal-title":"J Cachexia Sarcopenia Muscle"}],"container-title":["Orphanet Journal of Rare Diseases"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/article\/10.1186\/s13023-026-04332-3","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s13023-026-04332-3.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s13023-026-04332-3.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,17]],"date-time":"2026-06-17T22:48:25Z","timestamp":1781736505000},"score":1,"resource":{"primary":{"URL":"https:\/\/link.springer.com\/10.1186\/s13023-026-04332-3"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,23]]},"references-count":48,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2026,12]]}},"alternative-id":["4332"],"URL":"https:\/\/doi.org\/10.1186\/s13023-026-04332-3","relation":{},"ISSN":["1750-1172"],"issn-type":[{"value":"1750-1172","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,23]]},"assertion":[{"value":"21 November 2025","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"18 March 2026","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"23 April 2026","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"The study was approved by the local Ethics Committee (ID 2462 Prot. N. 0011843\/19, and ID 3717 Prot. N. 0050388\/20). Written informed consent was obtained from all participants or their legal guardians and a an explanation of the target protocol was fully provided, in conformity to the declaration of Helsinki.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and consent to participate"}},{"value":"Written informed consent for publication was obtained from all participants or their caregiver.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"The authors declare that they have no competing interests.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"223"}}