{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,24]],"date-time":"2026-01-24T04:18:43Z","timestamp":1769228323516,"version":"3.49.0"},"reference-count":25,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2023,12,13]],"date-time":"2023-12-13T00:00:00Z","timestamp":1702425600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Italian Ministry of Health","award":["RC2023"],"award-info":[{"award-number":["RC2023"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Children"],"abstract":"<jats:p>Congenital dermal melanocytosis (DM) represents a common birthmark mainly found in children of Asian and darker skin phototype descent, clinically characterized by an oval blue-grey macule or macules, commonly located on the lumbosacral area. In rare DM cases, when presenting with diffuse macules persisting during the first years of life, it could represent a cutaneous feature of mucopolysaccharidoses (MPS). Extensive congenital DM is actually associated with Hurler syndrome (MPS type I) and Hunter syndrome (MPS type II), although several reports also described this association with MPS type VI and other lysosomal storage disorders (LySD), including GM1 gangliosidosis, mucolipidosis, Sandhoff disease, and Niemann\u2013Pick disease. Here, we present the case of a two-year-old boy presenting with extensive dermal melanocytosis, generalized hypertrichosis, and chronic itch, harboring a heterozygous variant of uncertain significance, NM_152419.3: c.493C&gt;T (p.Pro165Ser), in the exon 4 of HGSNAT gene, whose mutations are classically associated with MPS IIIC, also known as Sanfilippo syndrome. This is the first report that highlights the association between extensive congenital DM and MPS type IIIC, as well as a pathogenetic link between heterozygous LySD carrier status and congenital DM. We speculate that some cases of extensive congenital DM could be related to heterozygous LySD carriers, as a manifestation of a mild clinical phenotype.<\/jats:p>","DOI":"10.3390\/children10121920","type":"journal-article","created":{"date-parts":[[2023,12,13]],"date-time":"2023-12-13T04:14:42Z","timestamp":1702440882000},"page":"1920","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Extensive and Persistent Dermal Melanocytosis in a Male Carrier of Mucopolysaccharidosis Type IIIC (Sanfilippo Syndrome): A Case Report"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7015-8319","authenticated-orcid":false,"given":"Maurizio","family":"Romagnuolo","sequence":"first","affiliation":[{"name":"Department of Pathophysiology and Transplantation, Universit\u00e0 degli Studi di Milano, 20122 Milan, Italy"},{"name":"Dermatology Unit, Fondazione IRCCS Ca\u2019 Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0060-5870","authenticated-orcid":false,"given":"Chiara","family":"Moltrasio","sequence":"additional","affiliation":[{"name":"Dermatology Unit, Fondazione IRCCS Ca\u2019 Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Serena","family":"Gasperini","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8160-4169","authenticated-orcid":false,"given":"Angelo Valerio","family":"Marzano","sequence":"additional","affiliation":[{"name":"Department of Pathophysiology and Transplantation, Universit\u00e0 degli Studi di Milano, 20122 Milan, Italy"},{"name":"Dermatology Unit, Fondazione IRCCS Ca\u2019 Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Stefano","family":"Cambiaghi","sequence":"additional","affiliation":[{"name":"Pediatric Dermatology Unit, Department of Clinical Sciences and Community Health, Fondazione IRCCS Ca\u2019 Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,12,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1016\/j.jaad.2022.01.051","article-title":"Disorders of hyperpigmentation. Part I. Pathogenesis and clinical features of common pigmentary disorders","volume":"88","author":"Wang","year":"2023","journal-title":"J. Am. Acad. Dermatol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"469","DOI":"10.4103\/0378-6323.113074","article-title":"Mongolian spots","volume":"79","author":"Gupta","year":"2013","journal-title":"Indian J. Dermatol. Venereol. Leprol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"480","DOI":"10.1097\/MOP.0000000000000247","article-title":"Dermal melanocytosis and associated disorders","volume":"27","author":"Franceschini","year":"2015","journal-title":"Curr. Opin. Pediatr."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"211","DOI":"10.4103\/ijpd.ijpd_66_22","article-title":"A Review of Dermal Melanocytosis","volume":"24","author":"Gautam","year":"2023","journal-title":"Indian J. Paediatr. Dermatol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"233","DOI":"10.1111\/j.1525-1470.2008.00641.x","article-title":"Superimposed Mongolian spots","volume":"25","author":"Leung","year":"2008","journal-title":"Pediatr. Dermatol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1111\/j.1365-4632.2004.02011.x","article-title":"Persistent Mongolian spots in Chinese adults","volume":"44","author":"Leung","year":"2005","journal-title":"Int. J. Dermatol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"594","DOI":"10.1111\/pde.12971","article-title":"Cutaneous Manifestations of Mucopolysaccharidoses","volume":"33","author":"Tran","year":"2016","journal-title":"Pediatr. Dermatol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"916","DOI":"10.1001\/archderm.139.7.916","article-title":"Association of dermal melanocytosis with lysosomal storage disease: Clinical features and hypotheses regarding pathogenesis","volume":"139","author":"Hanson","year":"2003","journal-title":"Arch. Dermatol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"218","DOI":"10.1542\/peds.58.2.218","article-title":"The incidence of birthmarks in the neonate","volume":"58","author":"Jacobs","year":"1976","journal-title":"Pediatrics"},{"key":"ref_10","unstructured":"Chua, R.F., and Pico, J. (2023, September 15). Dermal Melanocytosis [Updated 31 July 2023], StatPearls [Internet], Available online: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK557408\/."},{"key":"ref_11","first-page":"187","article-title":"Blue naevi and the blue tumour spectrum","volume":"55","year":"2023","journal-title":"Pathology"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2371","DOI":"10.1007\/s00381-018-3929-0","article-title":"A comprehensive review of Mongolian spots with an update on atypical presentations","volume":"34","author":"Alimi","year":"2018","journal-title":"Childs Nerv. Syst."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1111\/j.1365-4362.1982.tb02055.x","article-title":"What is a Mongolian spot?","volume":"21","author":"Kikuchi","year":"1982","journal-title":"Int. J. Dermatol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"224","DOI":"10.1111\/1523-1747.ep12514270","article-title":"on the extracellular sheath of dermal melanocytes in nevus fusco-ceruleus acromiodeltoideus (Ito) and Mongolian spot. An ultrastructural study","volume":"73","author":"Okawa","year":"1979","journal-title":"J. Investig. Dermatol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"456","DOI":"10.1002\/ajmg.1320470403","article-title":"Is there a relationship between inborn errors of metabolism and extensive mongolian spots?","volume":"47","author":"Mendez","year":"1993","journal-title":"Am. J. Med. Genet."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"276","DOI":"10.1002\/(SICI)1096-8628(19991126)87:3<276::AID-AJMG18>3.0.CO;2-C","article-title":"Is there a relationship between extensive mongolian spots and inborn errors of metabolism?","volume":"87","author":"Silengo","year":"1999","journal-title":"Am. J. Med. Genet."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1016\/j.pediatrneurol.2005.07.010","article-title":"Extensive Mongolian spots: A clinical sign merits special attention","volume":"34","author":"Ashrafi","year":"2006","journal-title":"Pediatr. Neurol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1082","DOI":"10.1111\/j.1468-3083.2007.02203.x","article-title":"Natural history of extensive Mongolian spots in mucopolysaccharidosis type II (Hunter syndrome): A survey among 52 Japanese patients","volume":"21","author":"Ochiai","year":"2007","journal-title":"J. Eur. Acad. Dermatol. Venereol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"e05122","DOI":"10.1002\/ccr3.5122","article-title":"A 1-year and 4-month-old child with mucopolysaccharidoses type II: A clinical case report from Ethiopia","volume":"9","author":"Deribessa","year":"2021","journal-title":"Clin. Case Rep."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1016\/j.ymgme.2013.07.016","article-title":"Glycan-based biomarkers for mucopolysaccharidoses","volume":"111","author":"Lawrence","year":"2014","journal-title":"Mol. Genet. Metab."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1016\/j.gene.2015.04.078","article-title":"Recurrent and novel GLB1 mutations in India","volume":"567","author":"Bidchol","year":"2015","journal-title":"Gene"},{"key":"ref_22","first-page":"34","article-title":"Clinical and Laboratory Profile of Gangliosidosis from Southern Part of India","volume":"11","author":"Gowda","year":"2020","journal-title":"J. Pediatr. Genet."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2051","DOI":"10.1007\/s11011-018-0315-2","article-title":"Clinical and molecular characteristics of 11 Chinese probands with GM1 gangliosidosis","volume":"33","author":"Feng","year":"2018","journal-title":"Metab. Brain Dis."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"736","DOI":"10.1111\/ijd.12303","article-title":"Diffuse dermal melanocytosis in two patients with Sandhoff disease and mucopolysaccharidosis VI","volume":"53","author":"Ashrafi","year":"2014","journal-title":"Int. J. Dermatol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"438","DOI":"10.1111\/j.1365-4632.2010.04262.x","article-title":"Extensive Mongolian spots in a child with mucolipidosis II","volume":"49","author":"Su","year":"2010","journal-title":"Int. J. Dermatol."}],"container-title":["Children"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2227-9067\/10\/12\/1920\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T21:37:46Z","timestamp":1760132266000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2227-9067\/10\/12\/1920"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,12,13]]},"references-count":25,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2023,12]]}},"alternative-id":["children10121920"],"URL":"https:\/\/doi.org\/10.3390\/children10121920","relation":{},"ISSN":["2227-9067"],"issn-type":[{"value":"2227-9067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,12,13]]}}}