{"id":177,"date":"2021-11-27T19:12:26","date_gmt":"2021-11-27T18:12:26","guid":{"rendered":"https:\/\/cerenef.org\/?page_id=177"},"modified":"2023-12-11T14:49:03","modified_gmt":"2023-12-11T13:49:03","slug":"formes-mosaiques-neurofibromatoses","status":"publish","type":"post","link":"https:\/\/cerenef.org\/en\/formes-mosaiques-neurofibromatoses\/","title":{"rendered":"Mosaic forms"},"content":{"rendered":"<div data-elementor-type=\"wp-page\" data-elementor-id=\"177\" class=\"elementor elementor-177\">\n\t\t\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-54eed3a elementor-section-boxed elementor-section-height-default elementor-section-height-default elementor-invisible\" data-id=\"54eed3a\" data-element_type=\"section\" data-e-type=\"section\" data-settings=\"{&quot;animation&quot;:&quot;fadeInLeft&quot;}\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-35122d1\" data-id=\"35122d1\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-2f262b6 elementor-widget elementor-widget-image\" data-id=\"2f262b6\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" src=\"https:\/\/cerenef.org\/wp-content\/uploads\/2022\/01\/forme-mosaique-neurofibromatoses.jpg\" title=\"CERENEF\" alt=\"CERENEF\" loading=\"lazy\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-b0433cc elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"b0433cc\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-e62f498\" data-id=\"e62f498\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-01e0691 elementor-widget elementor-widget-toggle\" data-id=\"01e0691\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"toggle.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-toggle\">\n\t\t\t\t\t\t\t<div class=\"elementor-toggle-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1961\" class=\"elementor-tab-title\" data-tab=\"1\" role=\"button\" aria-controls=\"elementor-tab-content-1961\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon elementor-toggle-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-closed\"><i class=\"fas fa-caret-right\"><\/i><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-opened\"><i class=\"elementor-toggle-icon-opened fas fa-caret-up\"><\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-toggle-title\" tabindex=\"0\">Definition<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<div id=\"elementor-tab-content-1961\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"1\" role=\"region\" aria-labelledby=\"elementor-tab-title-1961\"><p>Neurofibromatosis type 1 (NF1), Legius syndrome, neurofibromatosis type 2 (NF2), and schwannomatosis can manifest themselves in a so-called \"mosaic\" form. <\/p><p>These forms are linked to post-zygotic mutations in the genes involved in the same diseases. Thus, heterozygous mutations are not found in 100% of cells but in a variable percentage depending on the tissue removed (ranging from 0 to 100%). These molecular peculiarities are detailed <a href=\"https:\/\/cerenef.org\/en\/genetique-neurofibromatoses\/\">in the page dedicated<\/a> to genetics.<\/p><p>As a result, clinical involvement is not generalised or systemic but segmental (restricted to only certain cells of the body). These mosaic forms are often not severe.<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-toggle-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1962\" class=\"elementor-tab-title\" data-tab=\"2\" role=\"button\" aria-controls=\"elementor-tab-content-1962\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon elementor-toggle-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-closed\"><i class=\"fas fa-caret-right\"><\/i><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-opened\"><i class=\"elementor-toggle-icon-opened fas fa-caret-up\"><\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-toggle-title\" tabindex=\"0\">Diagnostic criteria for mosaic NF1<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<div id=\"elementor-tab-content-1962\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"2\" role=\"region\" aria-labelledby=\"elementor-tab-title-1962\"><p>The diagnostic criteria for mosaic NF1 are met in an individual if any of the following is present:<\/p><ul><li>A pathogenic heterozygous NF1 variant with a variant allele fraction of significantly less than 50% in apparently normal tissue such as white blood cells AND one other NF1 diagnostic criterion (except a parent fulfilling diagnostic criteria for NF1).<\/li><li>An identical pathogenic heterozygous NF1 variant in two anatomically independent affected tissues (in the absence of a pathogenic NF1 variant in unaffected tissue)<sup>*<\/sup>.<\/li><li>A clearly segmental distribution of caf\u00e9-au-lait macules or cutaneous neurofibromas\nand:<ul><li>Another NF1 diagnostic criterion (except a parent fulfilling diagnostic criteria for NF1<sup>**<\/sup>.<\/li><li>Or Child fulfilling diagnostic criteria for NF1.<\/li><\/ul><\/li><li>Only one NF1 diagnostic criterion from the following list: freckling in the axillary and inguinal region, optic pathway glioma, two or more Lisch nodules or two or more choroidal abnormalities, distinctive osseous lesion typical for NF1, two or more neurofibromas or one plexiform neurofibroma and a child fulfilling the criteria for NF1.<\/li><\/ul><hr \/><div id=\"references-italique\"><sup>*<\/sup>Neurofibroma and overlying hyperpigmented skin count for one tissue only; different tissues originating from the same primary affected lesion count for one tissue only.<br \/><sup>**<\/sup>If only \"caf\u00e9-au-lait\" macules and freckling are present, the diagnosis is most likely mosaic neurofibromatosis type 1 but rarely might be mosaic Legius syndrome or constitutional mismatch repair deficiency (CMMRD) syndrome.<\/div><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-toggle-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1963\" class=\"elementor-tab-title\" data-tab=\"3\" role=\"button\" aria-controls=\"elementor-tab-content-1963\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon elementor-toggle-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-closed\"><i class=\"fas fa-caret-right\"><\/i><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-opened\"><i class=\"elementor-toggle-icon-opened fas fa-caret-up\"><\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-toggle-title\" tabindex=\"0\">Diagnostics criteria for mosaic Legius syndrome<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<div id=\"elementor-tab-content-1963\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"3\" role=\"region\" aria-labelledby=\"elementor-tab-title-1963\"><p>Diagnosis of NF1 in mosaic is made when any of the following criteria are present:<\/p><ul><li>A heterozygous pathogenic SPRED1 variant with a variant allele fraction of significantly less than 50% in apparently normal tissue such as white blood cells and six or more \"caf\u00e9-au-lait\" macules.<\/li><li>An identical pathogenic heterozygous SPRED1 variant in two independent affected tissues (in the absence of a pathogenic SPRED1 variant inunaffected tissue)<sup>*<\/sup>.<\/li><li>A clearly segmental distribution of caf\u00e9-au-lait macules AND a child fulfilling the criteria for Legius syndrome.<\/li><\/ul><hr \/><div id=\"references-italique\"><sup>*<\/sup>Different tissues originating from the same primary affected lesion count for one tissue only.<\/div><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-toggle-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1964\" class=\"elementor-tab-title\" data-tab=\"4\" role=\"button\" aria-controls=\"elementor-tab-content-1964\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon elementor-toggle-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-closed\"><i class=\"fas fa-caret-right\"><\/i><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-opened\"><i class=\"elementor-toggle-icon-opened fas fa-caret-up\"><\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-toggle-title\" tabindex=\"0\">Patient care<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<div id=\"elementor-tab-content-1964\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"4\" role=\"region\" aria-labelledby=\"elementor-tab-title-1964\"><p>The diagnostic management of these mosaic forms is sometimes more complex and may require additional molecular analyses from other than blood samples, for instance, samples of hair, urine, skin, sperm, etc. The risk of transmission to the offspring of genuine NF1 or Legius syndrome is sometimes difficult to assess and analysing such biological samples may be useful.<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-toggle-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1965\" class=\"elementor-tab-title\" data-tab=\"5\" role=\"button\" aria-controls=\"elementor-tab-content-1965\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon elementor-toggle-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-closed\"><i class=\"fas fa-caret-right\"><\/i><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-toggle-icon-opened\"><i class=\"elementor-toggle-icon-opened fas fa-caret-up\"><\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-toggle-title\" tabindex=\"0\">Bibliographic references<\/a>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<div id=\"elementor-tab-content-1965\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"5\" role=\"region\" aria-labelledby=\"elementor-tab-title-1965\"><p>Legius E, Messiaen L, Wolkenstein P, Pancza P, Avery RA, Do G. Revised diagnostic criteria for neurofibromatosis type 1 and Legius syndrome: an international consensus recommendation. Genet Med. Published online May 19, 2021. doi:10.1038\/s41436-021-01170-5<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>","protected":false},"excerpt":{"rendered":"<p>D\u00e9finition La neurofibromatose de type 1 (NF1), le syndrome de Legius, la neurofibromatose de type 2 (NF2), les schwannomatoses peuvent se manifester sous une forme dite \u00ab en mosa\u00efque \u00bb. Ces formes sont li\u00e9es \u00e0 des mutations post-zygotiques des g\u00e8nes impliqu\u00e9s dans les m\u00eames maladies. Ainsi, les mutations h\u00e9t\u00e9rozygotes ne sont pas retrouv\u00e9es dans 100%&hellip;&nbsp;<\/p>\n<div class=\"read-more-wrapper\"><a href=\"https:\/\/cerenef.org\/en\/formes-mosaiques-neurofibromatoses\/\" class=\"button button-secondary\" rel=\"bookmark\">\u279c Read more<span class=\"screen-reader-text\">Mosaic forms<\/span><\/a><\/div>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"off","neve_meta_content_width":100,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","neve_meta_reading_time":"","footnotes":""},"categories":[17],"tags":[],"class_list":["post-177","post","type-post","status-publish","format-standard","hentry","category-les-neurofibromatoses"],"_links":{"self":[{"href":"https:\/\/cerenef.org\/en\/wp-json\/wp\/v2\/posts\/177","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cerenef.org\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cerenef.org\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cerenef.org\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cerenef.org\/en\/wp-json\/wp\/v2\/comments?post=177"}],"version-history":[{"count":0,"href":"https:\/\/cerenef.org\/en\/wp-json\/wp\/v2\/posts\/177\/revisions"}],"wp:attachment":[{"href":"https:\/\/cerenef.org\/en\/wp-json\/wp\/v2\/media?parent=177"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cerenef.org\/en\/wp-json\/wp\/v2\/categories?post=177"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cerenef.org\/en\/wp-json\/wp\/v2\/tags?post=177"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}