{"id":117076,"date":"2025-10-01T12:13:20","date_gmt":"2025-10-01T03:13:20","guid":{"rendered":"https:\/\/www.hiro-clinic.or.jp\/nipt\/chromosome-9p24-3-deletion-syndrome\/"},"modified":"2025-10-01T16:49:39","modified_gmt":"2025-10-01T07:49:39","slug":"chromosome-9p24-3-deletion-syndrome","status":"publish","type":"post","link":"https:\/\/www.hiro-clinic.or.jp\/nipt\/chromosome-9p24-3-deletion-syndrome\/?lang=en","title":{"rendered":"9p24.3 Deletion Syndrome"},"content":{"rendered":"\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_83 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">\u76ee\u6b21<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/chromosome-9p24-3-deletion-syndrome\/?lang=en\/#Alternate_Names\" >Alternate Names<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/chromosome-9p24-3-deletion-syndrome\/?lang=en\/#Disorder_Overview\" >Disorder Overview<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/chromosome-9p24-3-deletion-syndrome\/?lang=en\/#Deletion_Range_and_Candidate_Genes\" >Deletion Range and Candidate Genes<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/chromosome-9p24-3-deletion-syndrome\/?lang=en\/#Clinical_Features_Typical_Findings\" >Clinical Features (Typical Findings)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/chromosome-9p24-3-deletion-syndrome\/?lang=en\/#Epidemiology_Incidence\" >Epidemiology \/ Incidence<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/chromosome-9p24-3-deletion-syndrome\/?lang=en\/#Etiology_Diagnostic_Methods\" >Etiology &amp; Diagnostic Methods<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/chromosome-9p24-3-deletion-syndrome\/?lang=en\/#Etiology_Pathogenesis\" >Etiology \/ Pathogenesis<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/chromosome-9p24-3-deletion-syndrome\/?lang=en\/#Diagnostic_Methods\" >Diagnostic Methods<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/chromosome-9p24-3-deletion-syndrome\/?lang=en\/#Symptoms_Management\" >Symptoms &amp; Management<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/chromosome-9p24-3-deletion-syndrome\/?lang=en\/#Main_Symptoms_Issues\" >Main Symptoms \/ Issues<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/chromosome-9p24-3-deletion-syndrome\/?lang=en\/#Management_Therapeutic_Strategies\" >Management \/ Therapeutic Strategies<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Alternate_Names\"><\/span><strong>Alternate Names<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>9p24.3 Deletion Syndrome<br><\/li>\n\n\n\n<li>9p short arm partial deletion (particularly in the 9p24.3 region)<br><\/li>\n\n\n\n<li>A subtype of 9p deletion syndrome (9p deletion syndrome \/ 9p\u2011syndrome)<br><\/li>\n\n\n\n<li>9p minus syndrome (especially the \u201cterminal deletion\u201d type)<br><\/li>\n\n\n\n<li>Sometimes regarded as a subtype of Alfi syndrome (referring to the broader 9p deletion spectrum)<br><\/li>\n<\/ul>\n\n\n\n<p>This name indicates that some or all of the genes near the terminal region (24.3) of the p arm of chromosome 9 are deleted on one copy. Within the broader framework of 9p deletion (9p deletion syndrome), the term \u201c9p24.3 deletion syndrome\u201d is used when the deletion breakpoint is close to 24.3.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Disorder_Overview\"><\/span><strong>Disorder Overview<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>9p24.3 Deletion Syndrome is a chromosomal abnormality in which one copy of the genes in the terminal region near 9p24.3 is lost (i.e. haploinsufficiency), leading to reduced gene dosage and a spectrum of developmental, structural, and functional abnormalities. The clinical presentation and severity vary widely depending on the exact deletion range (which genes are lost), whether additional chromosomal abnormalities are present, and individual variation. Thus, phenotypes range from mild to severe.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Deletion_Range_and_Candidate_Genes\"><\/span><strong>Deletion Range and Candidate Genes<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>In large\u2011scale studies of 9p deletions overall, many deletion breakpoints have been reported around 9p22 and 9p24, making the 9p24 region a mutational hotspot.<br>Within 9p24.3 deletions, there are numerous candidate genes such as <strong>DOCK8<\/strong>, <strong>KANK1<\/strong>, <strong>DMRT1<\/strong>, <strong>DMRT2<\/strong>, <strong>DMRT3<\/strong>, <strong>FOXD4<\/strong>, <strong>SMARCA2<\/strong>, among others.<br>In particular, DOCK8 and KANK1 are implicated in neurodevelopment, behavioral regulation, and immune function; their loss may be associated with neurodevelopmental disorders, seizure predisposition, and autism spectrum\u2013like features in deletion cases.<br>Additionally, the DMRT gene family (involved in sexual differentiation) is of interest in cases of genital abnormalities or sex differentiation disorders. Some male (XY) cases have been reported with genital malformations associated with 9p24.3 deletion.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Clinical_Features_Typical_Findings\"><\/span><strong>Clinical Features (Typical Findings)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>From reported cases, the main clinical features include (but are not present in every case):<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Developmental delay, intellectual disability (moderate to severe)<br><\/li>\n\n\n\n<li>Delayed language development, difficulty in speech<br><\/li>\n\n\n\n<li>Facial dysmorphism: triangular skull (narrow frontal region), midface hypoplasia, low\u2011set ears, broad nasal bridge, long philtrum, thin upper lip, etc.<br><\/li>\n\n\n\n<li>Congenital heart defects (e.g. ventricular septal defect, atrial septal defect)<br><\/li>\n\n\n\n<li>Genital abnormalities \/ sex differentiation disorders: in male cases, underdevelopment of external genitalia, cryptorchidism, etc.<br><\/li>\n\n\n\n<li>Behavioral abnormalities, autism spectrum\u2013like features, attention deficit, hyperactivity tendency<br><\/li>\n\n\n\n<li>Immune dysfunction predisposition, frequent infections (especially in some DOCK8 deletion cases)<br><\/li>\n\n\n\n<li>Others: urinary tract anomalies, limb deformities, visual abnormalities (e.g. strabismus, optic nerve developmental defects), reduced motor coordination, muscle tone abnormalities<br><\/li>\n<\/ul>\n\n\n\n<p>Because published cases are limited, pure 9p24.3 deletion (without other chromosomal anomalies) is considered relatively rare, and is often regarded as a variant within the 9p deletion spectrum.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Epidemiology_Incidence\"><\/span><strong>Epidemiology \/ Incidence<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>For the broader 9p deletion syndrome, more than 100 cases have been reported, although the true incidence is unknown.<br>Cases limited to 9p24.3 deletion are even fewer; only a handful have been documented in the literature.<br>In most cases, the deletion is <strong>de novo<\/strong> (new mutation), with no similar abnormality in the parents. However, in rare instances, parents may carry a balanced translocation that is passed on in an unbalanced form to offspring.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Etiology_Diagnostic_Methods\"><\/span><strong>Etiology &amp; Diagnostic Methods<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Etiology_Pathogenesis\"><\/span><strong>Etiology \/ Pathogenesis<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The deletion typically arises from chromosomal breakage and aberrant recombination; the timing is presumed to be during gametogenesis or early post\u2011fertilization.<br><\/li>\n\n\n\n<li>If a parent carries a balanced chromosomal rearrangement (e.g. translocations, inversions), there is a risk that an unbalanced form may be transmitted to a child.<br><\/li>\n\n\n\n<li>The deletion causes <strong>haploinsufficiency<\/strong>, meaning that one copy of the gene is insufficient to sustain normal function, thereby disrupting development and structural formation.<br><\/li>\n\n\n\n<li>Interaction with genes outside the deletion region, dysregulation of gene networks, and influence of modifier genes are also considered key factors in phenotypic variability.<br><\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Diagnostic_Methods\"><\/span><strong>Diagnostic Methods<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Clinical suspicion and physical examination<\/strong><strong><br><\/strong> Based on developmental delay, facial dysmorphism, heart defects, genital abnormalities, etc.<br><\/li>\n\n\n\n<li><strong>Karyotype (standard chromosomal analysis)<\/strong><strong><br><\/strong> If the deletion is large, G\u2011band karyotyping may detect it.<br><\/li>\n\n\n\n<li><strong>FISH (fluorescence in situ hybridization)<\/strong><strong><br><\/strong> Use of specific probes to check for deletion in the 9p24.3 region.<br><\/li>\n\n\n\n<li><strong>Microarray Comparative Genomic Hybridization \/ SNP microarray (array CGH \/ SNP array)<\/strong><strong><br><\/strong> High resolution detection of deletions or duplications, capable of identifying microdeletions.<br><\/li>\n\n\n\n<li><strong>Next\u2011generation sequencing (NGS) as adjunctive assay<\/strong><strong><br><\/strong> May be used to further characterize gene variants within the deleted region.<br><\/li>\n\n\n\n<li><strong>Parental testing \/ Genetic counseling<\/strong><strong><br><\/strong> Testing parents\u2019 chromosomes to see if they carry balanced rearrangements, helping to assess recurrence risk and aid family planning.<br><\/li>\n\n\n\n<li><strong>Supplementary investigations<\/strong><strong><br><\/strong> Echocardiography, endocrine \/ sexual hormone assays, immune function tests, urinary system evaluation, imaging (e.g. brain MRI), etc., to assess and manage associated anomalies.<br><\/li>\n<\/ol>\n\n\n\n<p>By this stepwise diagnostic approach, a definitive diagnosis can be reached.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" width=\"640\" height=\"427\" src=\"\/nipt\/wp-content\/uploads\/2025\/09\/32617927_s-4.webp\" alt=\"\u533b\u8005\" class=\"wp-image-116067\"\/><\/figure><\/div>\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Symptoms_Management\"><\/span><strong>Symptoms &amp; Management<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Main_Symptoms_Issues\"><\/span><strong>Main Symptoms \/ Issues<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Developmental delay, intellectual disability<br><\/li>\n\n\n\n<li>Delayed language development, speech difficulty<br><\/li>\n\n\n\n<li>Facial dysmorphism (skull shape, ear \/ nose \/ mouth morphology)<br><\/li>\n\n\n\n<li>Congenital heart defects<br><\/li>\n\n\n\n<li>Genital abnormalities \/ sex differentiation disorders<br><\/li>\n\n\n\n<li>Behavioral abnormalities, autism spectrum traits, attention deficit \/ hyperactivity<br><\/li>\n\n\n\n<li>Immune system impairment, frequent infections<br><\/li>\n\n\n\n<li>Visual abnormalities, nystagmus, strabismus, optic nerve hypoplasia<br><\/li>\n\n\n\n<li>Other anomalies: urinary system, limbs, kidney, etc.<br><\/li>\n\n\n\n<li>Muscle tone abnormalities, reduced motor coordination<br><\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Management_Therapeutic_Strategies\"><\/span><strong>Management \/ Therapeutic Strategies<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Developmental support \/ <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/early-nipt-august-only\/\">Early<\/a> intervention<\/strong><strong><br><\/strong> Provide physical therapy, occupational therapy, speech therapy, and developmental support from infancy to maximize motor, cognitive, and language function.<br><\/li>\n\n\n\n<li><strong>Management of cardiac defects<\/strong><strong><br><\/strong> Collaborate with cardiac specialists; if heart defects are present, consider surgical or medical management, with regular cardiac follow-up.<br><\/li>\n\n\n\n<li><strong>Sex \/ endocrine management<\/strong><strong><br><\/strong> For cases with genital anomalies, perform endocrine evaluations, consider hormone replacement or surgical intervention when needed.<br><\/li>\n\n\n\n<li><strong>Immune function management \/ Infection prevention<\/strong><strong><br><\/strong> Monitor immune function, and in cases of immune deficiency, implement vaccinations, infection prevention measures, and early treatment.<br><\/li>\n\n\n\n<li><strong>Behavioral \/ psychiatric care<\/strong><strong><br><\/strong> Use behavioral therapy, environmental structuring, psychological support, and medications if needed to manage behavioral problems or attention deficit.<br><\/li>\n\n\n\n<li><strong>Vision \/ hearing support<\/strong><strong><br><\/strong> Regular ophthalmology and otolaryngology assessments; interventions may include strabismus correction, vision correction, and assistive devices (e.g. hearing aids).<br><\/li>\n\n\n\n<li><strong>Regular monitoring<\/strong><strong><br><\/strong> Periodically assess growth and development, cardiac\/renal\/urinary systems, neurodevelopment, vision\/hearing, and intervene as needed.<br><\/li>\n\n\n\n<li><strong>Educational \/ social \/ welfare support<\/strong><strong><br><\/strong> Collaborate with special education and therapy institutions, use assistive devices, day support, employment support, disability welfare systems, and caregiving structures to build a comprehensive support network.<br><\/li>\n\n\n\n<li><strong>Family support<\/strong><strong><br><\/strong> Provide psychological support, counseling services, respite care, and early planning for future care systems for caregivers and family members.<br><\/li>\n<\/ul>\n\n\n\n<p>Integrating these strategies to form a comprehensive, individualized support system for each patient and family is crucial.<\/p>\n","protected":false},"excerpt":{"rendered":"Alternate Names This&#8230;\n <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/chromosome-9p24-3-deletion-syndrome\/?lang=en\">\u7d9a\u304d\u3092\u8aad\u3080<\/a>","protected":false},"author":122,"featured_media":117056,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[97],"tags":[],"class_list":["post-117076","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/posts\/117076","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/users\/122"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/comments?post=117076"}],"version-history":[{"count":6,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/posts\/117076\/revisions"}],"predecessor-version":[{"id":117096,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/posts\/117076\/revisions\/117096"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/media\/117056"}],"wp:attachment":[{"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/media?parent=117076"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/categories?post=117076"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/tags?post=117076"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}