{"id":84338,"date":"2024-11-15T15:52:39","date_gmt":"2024-11-15T06:52:39","guid":{"rendered":"https:\/\/www.hiro-clinic.or.jp\/nipt\/15q26-qter-deletion-syndrome\/"},"modified":"2026-07-12T21:22:09","modified_gmt":"2026-07-12T12:22:09","slug":"15q26-qter-deletion-syndrome","status":"publish","type":"post","link":"https:\/\/www.hiro-clinic.or.jp\/nipt\/15q26-qter-deletion-syndrome\/?lang=en","title":{"rendered":"15q26-qter Deletion Syndrome"},"content":{"rendered":"\n

If you’ve just heard the diagnosis “15q26-qter deletion syndrome” or seen it on a test result, an unfamiliar term like this can feel unsettling.<\/strong><\/p>\n\n\n\n

Here is the short answer first. This condition is caused by the loss of the region from the middle of the long arm “26” of chromosome 15 all the way to its tip (the telomeric end, or “qter”), and only a few dozen cases have ever been reported worldwide, making it an extremely rare chromosomal disorder.<\/strong> A shortage of the IGF1R gene, one of the growth-related receptor genes in this region, is the main driver behind prenatal growth delay and short stature, while some cases \u2014 depending on how much of the chromosome is missing \u2014 also involve heart defects or diaphragm abnormalities.<\/p>\n\n\n\n

This article walks through the chromosomal change that causes the condition, how it differs from other chromosome 15 disorders (Prader-Willi syndrome, and the mirror-image condition, 15q26 overgrowth syndrome), the symptoms, inheritance patterns, its relationship to prenatal diagnosis and NIPT<\/a>, the path to a definitive diagnosis, and the outlook for treatment \u2014 all based on public and academic sources including GARD, Orphanet, and peer-reviewed case reports. Let’s go through it one step at a time.<\/p>\n\n\n\n

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\ud83d\udca1 What you’ll learn in this article<\/p>\n