{"id":116078,"date":"2025-09-24T17:15:41","date_gmt":"2025-09-24T08:15:41","guid":{"rendered":"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/"},"modified":"2025-10-14T12:45:30","modified_gmt":"2025-10-14T03:45:30","slug":"nipt-chromosome-abnormality","status":"publish","type":"post","link":"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en","title":{"rendered":"Types of Chromosomal Abnormalities Detectable by NIPT"},"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\/nipt-chromosome-abnormality\/?lang=en\/#Introduction\" >Introduction<\/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\/nipt-chromosome-abnormality\/?lang=en\/#1_What_is_NIPT\" >1. What is NIPT?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\/#2_Types_of_Chromosomal_Abnormalities_Detectable_by_NIPT\" >2. Types of Chromosomal Abnormalities Detectable by NIPT<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\/#2%E2%80%911_Trisomy_21_Down_Syndrome\" >2\u20111. Trisomy 21 (Down Syndrome)<\/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\/nipt-chromosome-abnormality\/?lang=en\/#2%E2%80%912_Trisomy_18_Edwards_Syndrome\" >2\u20112. Trisomy 18 (Edwards Syndrome)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\/#2%E2%80%913_Trisomy_13_Patau_Syndrome\" >2\u20113. Trisomy 13 (Patau Syndrome)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\/#2%E2%80%914_Sex_Chromosome_Abnormalities\" >2\u20114. Sex Chromosome Abnormalities<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\/#3_Detection_of_Microdeletions_and_Duplications\" >3. Detection of Microdeletions and Duplications<\/a><\/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\/nipt-chromosome-abnormality\/?lang=en\/#4_Accuracy_and_Limitations_of_NIPT\" >4. Accuracy and Limitations of NIPT<\/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\/nipt-chromosome-abnormality\/?lang=en\/#4%E2%80%911_Accuracy\" >4\u20111. Accuracy<\/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\/nipt-chromosome-abnormality\/?lang=en\/#4%E2%80%912_Limitations\" >4\u20112. Limitations<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\/#5_When_and_How_to_Take_NIPT\" >5. When and How to Take NIPT<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\/#6_Key_Considerations_When_Choosing_NIPT\" >6. Key Considerations When Choosing NIPT<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\/#7_Summary_So_Far\" >7. Summary So Far<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\/#8_Latest_Advances_and_Expanded_Scope_in_NIPT\" >8. Latest Advances and Expanded Scope in NIPT<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\/#8%E2%80%911_Use_of_Microarray_Analysis\" >8\u20111. Use of Microarray Analysis<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\/#8%E2%80%912_Improved_Detection_of_Sex_Chromosome_Abnormalities\" >8\u20112. Improved Detection of Sex Chromosome Abnormalities<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\/#9_Statistics_and_Usage_in_Japan\" >9. Statistics and Usage in Japan<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\/#10_Ethical_Considerations_of_NIPT\" >10. Ethical Considerations of NIPT<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\/#11_Cost_and_Insurance_Coverage\" >11. Cost and Insurance Coverage<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\/#12_How_to_Choose_the_Right_NIPT\" >12. How to Choose the Right NIPT<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-22\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\/#13_Conclusion\" >13. Conclusion<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Introduction\"><\/span><strong>Introduction<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> (Non-Invasive Prenatal Testing) has garnered attention as a prenatal screening method during pregnancy. By analyzing fetal DNA present in the mother&#8217;s blood, it enables early detection of various chromosomal abnormalities. Compared to traditional invasive tests such as amniocentesis or chorionic villus sampling, <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> poses less risk to both the mother and fetus and offers high accuracy, making it a preferred option for many expectant mothers.<br>This article provides a detailed explanation of the types of chromosomal abnormalities detectable by <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a>, how the test works, its accuracy and limitations, and important considerations when choosing to undergo testing.<\/p>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"1_What_is_NIPT\"><\/span>1. What is NIPT?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> analyzes <strong>cell-free fetal DNA (cfDNA)<\/strong> circulating in the maternal blood to assess the likelihood of chromosomal abnormalities in the fetus.<br>Fetal DNA can be detected from early pregnancy, and testing is generally conducted from the 10th week of gestation. A key feature of <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> is that it carries almost no risk of miscarriage, unlike invasive procedures.<\/p>\n\n\n\n<p><strong>How <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> Works:<\/strong><\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Blood sample collection from the mother<\/li>\n\n\n\n<li>Extraction of cfDNA<\/li>\n\n\n\n<li>Chromosomal analysis using Next-Generation Sequencing (NGS)<\/li>\n\n\n\n<li>Evaluation of chromosomal number abnormalities<\/li>\n<\/ol>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"2_Types_of_Chromosomal_Abnormalities_Detectable_by_NIPT\"><\/span>2. Types of Chromosomal Abnormalities Detectable by NIPT<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> primarily detects numerical chromosomal abnormalities (trisomies and monosomies). Below are the most common conditions:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"2%E2%80%911_Trisomy_21_Down_Syndrome\"><\/span>2\u20111. Trisomy 21 (Down Syndrome)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>This is the most common chromosomal abnormality, caused by an extra copy of chromosome 21.<br>Physical traits include short stature, flat facial profile, upslanted eye fissures, and intellectual disability.<br><a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> can detect this condition with over 99% sensitivity and specificity.<\/p>\n\n\n\n<p><em>Reference: Bianchi DW et al., N Engl J Med, 2014;370:799\u2011808<\/em><\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"2%E2%80%912_Trisomy_18_Edwards_Syndrome\"><\/span>2\u20112. Trisomy 18 (Edwards Syndrome)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Trisomy 18 results from an extra chromosome 18. It is often associated with severe congenital heart and kidney defects, developmental delays, and typically short life expectancy after birth.<br>Detection sensitivity is around 97\u201399% and specificity is approximately 99%.<\/p>\n\n\n\n<p><em>Reference: Palomaki GE et al., Genet Med, 2012;14:296\u2011305<\/em><\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"2%E2%80%913_Trisomy_13_Patau_Syndrome\"><\/span>2\u20113. Trisomy 13 (Patau Syndrome)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Caused by an extra chromosome 13, this condition involves multiple congenital anomalies and typically short survival.<br>Detection sensitivity is approximately 90\u201395%, with specificity near 99%.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"2%E2%80%914_Sex_Chromosome_Abnormalities\"><\/span>2\u20114. Sex Chromosome Abnormalities<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p><a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> can also detect abnormalities in the sex chromosomes (X and Y).<br>Examples include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Turner Syndrome (45,X):<\/strong> Female missing one X chromosome; may have short stature, ovarian dysfunction<\/li>\n\n\n\n<li><strong>Klinefelter Syndrome (47,XXY):<\/strong> Male with an extra X chromosome; tall stature, infertility, and learning difficulties<\/li>\n\n\n\n<li><strong>Triple X Syndrome (47,XXX):<\/strong> Female with an extra X chromosome; may have mild intellectual and reproductive issues<\/li>\n\n\n\n<li><strong>Jacobs Syndrome (47,XYY):<\/strong> Male with an extra Y chromosome; typically mild physical and cognitive effects<\/li>\n<\/ul>\n\n\n\n<p><em>Reference: Norton ME et al., N Engl J Med, 2015;372:1589\u20111597<\/em><\/p>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"3_Detection_of_Microdeletions_and_Duplications\"><\/span>3. Detection of Microdeletions and Duplications<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Advancements in technology have enabled the detection of certain <strong>microdeletions and microduplications<\/strong>, in addition to common trisomies and monosomies.<br>For example, <strong>22q11.2 deletion syndrome (DiGeorge syndrome)<\/strong> involves cardiac defects, immune system abnormalities, and intellectual disabilities, and can now be screened via <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> in some settings.<\/p>\n\n\n\n<p><em>Reference: Liang D et al., Prenat Diagn, 2018;38:789\u2011797<\/em><\/p>\n\n\n\n<p>However, detection of microabnormalities has lower sensitivity and higher false-positive rates. Positive results should be followed by confirmatory testing (amniocentesis or chorionic villus sampling).<\/p>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"4_Accuracy_and_Limitations_of_NIPT\"><\/span>4. Accuracy and Limitations of NIPT<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"4%E2%80%911_Accuracy\"><\/span>4\u20111. Accuracy<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Trisomy 21: Sensitivity >99%, Specificity >99%<\/li>\n\n\n\n<li>Trisomy 18: Sensitivity ~97\u201399%, Specificity ~99%<\/li>\n\n\n\n<li>Trisomy 13: Sensitivity ~90\u201395%, Specificity ~99%<\/li>\n\n\n\n<li>Sex Chromosome Abnormalities: Sensitivity 85\u201395%, Specificity ~99%<\/li>\n<\/ul>\n\n\n\n<p><em>Reference: Gil MM et al., Ultrasound Obstet Gynecol, 2015;45:530\u2011539<\/em><\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"4%E2%80%912_Limitations\"><\/span>4\u20112. Limitations<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>False Positives\/Negatives:<\/strong><br>Maternal cfDNA can affect results, especially if the mother has chromosomal abnormalities or tumors.<\/li>\n\n\n\n<li><strong>Detection Limits:<\/strong><br>Microdeletions\/duplications under 5\u201310 Mb are difficult to detect.<\/li>\n\n\n\n<li><strong>Not a Diagnostic Test:<\/strong><br><a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> is a screening test. Positive results require confirmatory diagnostic testing.<\/li>\n<\/ul>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"5_When_and_How_to_Take_NIPT\"><\/span>5. When and How to Take NIPT<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Consult with your OB-GYN after 10 weeks of pregnancy<\/li>\n\n\n\n<li>Blood collection<\/li>\n\n\n\n<li>Sample sent to a lab<\/li>\n\n\n\n<li>Results provided (usually within 1\u20132 weeks)<\/li>\n\n\n\n<li>If positive, discuss confirmatory testing with your doctor<\/li>\n<\/ol>\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\/32943421_s.webp\" alt=\"\u598a\u5a66\" class=\"wp-image-116072\"\/><\/figure><\/div>\n\n\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"6_Key_Considerations_When_Choosing_NIPT\"><\/span>6. Key Considerations When Choosing NIPT<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Understand that <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> is a screening, <strong>not a diagnostic<\/strong> test<\/li>\n\n\n\n<li>Detection sensitivity for sex chromosome and microdeletion abnormalities is relatively lower<\/li>\n\n\n\n<li>The types of chromosomal abnormalities tested vary by institution<\/li>\n\n\n\n<li>Genetic counseling is recommended due to the potential psychological impact of results<\/li>\n<\/ul>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"7_Summary_So_Far\"><\/span>7. Summary So Far<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> is a highly accurate and low-risk screening method that allows early detection of major chromosomal abnormalities such as Trisomy 21, 18, and 13. The detection scope has expanded in recent years to include microdeletions.<br>However, it remains a screening\u2014not a diagnostic\u2014tool, and its accuracy has limits, particularly for sex chromosome and microdeletion abnormalities. Proper use in consultation with a doctor or genetic counselor can help enhance prenatal care options and support safe pregnancy management.<\/p>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"8_Latest_Advances_and_Expanded_Scope_in_NIPT\"><\/span>8. Latest Advances and Expanded Scope in NIPT<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"8%E2%80%911_Use_of_Microarray_Analysis\"><\/span>8\u20111. Use of Microarray Analysis<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>With microarray technology, <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> can detect some microdeletions\/duplications previously undetectable.<br>Examples include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>22q11.2 Deletion Syndrome<\/li>\n\n\n\n<li><a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/1p-36-deletion-syndrome\/\">1p36<\/a> Deletion Syndrome<\/li>\n\n\n\n<li>15q11.2 Deletion Syndrome (Prader-Willi, Angelman Syndromes)<\/li>\n<\/ul>\n\n\n\n<p>These have lower sensitivity and specificity; positive results require confirmatory testing.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"8%E2%80%912_Improved_Detection_of_Sex_Chromosome_Abnormalities\"><\/span>8\u20112. Improved Detection of Sex Chromosome Abnormalities<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>NGS has improved the detection accuracy of conditions like Turner and Klinefelter syndromes. However, due to the risk of false positives, counseling and confirmatory testing remain essential.<\/p>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"9_Statistics_and_Usage_in_Japan\"><\/span>9. Statistics and Usage in Japan<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Since its introduction in Japan in 2013, the number of <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> facilities has increased, with over 100,000 tests performed annually.<br>Initially focused on advanced maternal age (35+), <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> is now used across all age groups.<br>Positive predictive value (PPV) for Down syndrome varies by age and gestational week:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Over age 35: ~90%<\/li>\n\n\n\n<li>Around age 30: ~60\u201370%<\/li>\n<\/ul>\n\n\n\n<p><em>Reference: Akolekar R et al., Ultrasound Obstet Gynecol, 2015;45:530\u2011539<\/em><\/p>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"10_Ethical_Considerations_of_NIPT\"><\/span>10. Ethical Considerations of NIPT<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>While <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> provides valuable genetic information, ethical and psychological considerations are important:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Positive results indicate <strong>possibility<\/strong>, not confirmation<\/li>\n\n\n\n<li>The information may cause emotional stress for families<\/li>\n\n\n\n<li>Some chromosomal abnormalities have only mild symptoms<\/li>\n\n\n\n<li>Sex chromosome abnormalities may influence prenatal decisions<\/li>\n<\/ul>\n\n\n\n<p>Genetic counseling is recommended to explain test limitations, interpret results, and consider next steps.<\/p>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"11_Cost_and_Insurance_Coverage\"><\/span>11. Cost and Insurance Coverage<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>In Japan, <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> typically costs around \u00a5150,000\u2013\u00a5200,000.<br>Currently, it is not covered by health insurance and is paid out-of-pocket, even for high-risk pregnancies.<br>Be aware of additional costs such as counseling and follow-up diagnostics.<\/p>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"12_How_to_Choose_the_Right_NIPT\"><\/span>12. How to Choose the Right NIPT<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Clarify your purpose<\/strong>: Screening for major trisomies only? Or include microdeletions?<\/li>\n\n\n\n<li><strong>Understand test accuracy<\/strong>: High for Trisomy 21; lower for sex chromosomes and microdeletions<\/li>\n\n\n\n<li><strong>Receive counseling<\/strong>: Prepare for emotional impact and future decisions<\/li>\n\n\n\n<li><strong>Be ready for follow-up testing<\/strong>: Positive results should be confirmed via diagnostic testing<\/li>\n<\/ul>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"13_Conclusion\"><\/span>13. Conclusion<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> is a revolutionary prenatal screening tool with high accuracy and minimal risk to both mother and fetus. Its scope now includes sex chromosome and microdeletion abnormalities.<br>However, it is not a diagnostic test, and positive results require further confirmation. Understanding its limitations and receiving appropriate counseling ensures better decision-making and peace of mind during pregnancy management.<\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"Introduction NIPT (N&#8230;\n <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt-chromosome-abnormality\/?lang=en\">\u7d9a\u304d\u3092\u8aad\u3080<\/a>","protected":false},"author":122,"featured_media":116069,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[97],"tags":[],"class_list":["post-116078","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\/116078","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=116078"}],"version-history":[{"count":3,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/posts\/116078\/revisions"}],"predecessor-version":[{"id":118030,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/posts\/116078\/revisions\/118030"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/media\/116069"}],"wp:attachment":[{"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/media?parent=116078"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/categories?post=116078"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/tags?post=116078"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}