{"id":4422448,"date":"2025-01-11T19:27:52","date_gmt":"2025-01-12T01:27:52","guid":{"rendered":"https:\/\/myendoconsult.com\/learn\/topics\/turner-syndrome\/"},"modified":"2025-01-26T17:54:08","modified_gmt":"2025-01-26T23:54:08","slug":"turner-syndrome","status":"publish","type":"oen_topic","link":"https:\/\/myendoconsult.com\/learn\/topics\/turner-syndrome\/","title":{"rendered":"Turner Syndrome"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">TURNER SYNDROME (GONADAL DYSGENESIS)<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Overview<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Definition<\/strong>: Turner syndrome, or X-chromosome monosomy, is a leading consideration in <strong>short-stature females<\/strong> with <strong>primary amenorrhea<\/strong>.<\/li>\n\n\n\n<li><strong>Incidence<\/strong>: ~1 in 2500 live-born phenotypic female births.<\/li>\n\n\n\n<li><strong>Classical Features<\/strong> (described by Turner, 1938):\n<ul class=\"wp-block-list\">\n<li><strong><a href=\"https:\/\/myendoconsult.com\/learn\/evaluation-of-short-stature\/\" data-wpil-monitor-id=\"214\">Short stature<\/a><\/strong><\/li>\n\n\n\n<li><strong>Webbed neck (pterygium colli)<\/strong><\/li>\n\n\n\n<li><strong>Cubitus valgus<\/strong> (forearm angle)<\/li>\n\n\n\n<li><strong>Broad, shield-like chest<\/strong><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Karyotypes<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>45,X<\/strong> (most common)<\/li>\n\n\n\n<li><strong>Mosaic forms<\/strong> (e.g., 45,X\/46,XX; 45,X\/46,XY)<\/li>\n\n\n\n<li><strong>Structural abnormalities<\/strong> of the X chromosome (e.g., deletions, ring chromosome)<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Cause<\/strong>: Typically nondisjunction or chromosome loss during gametogenesis in either parent.\n<ul class=\"wp-block-list\">\n<li>~1\/3 retain <strong>paternal X<\/strong>; 2\/3 retain <strong>maternal X<\/strong>.<\/li>\n\n\n\n<li>~25% have <strong>mosaicism<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"3000\" height=\"2100\" src=\"https:\/\/myendoconsult.com\/learn\/wp-content\/uploads\/Turner-syndrome.png\" alt=\"\" class=\"wp-image-4423057\" srcset=\"https:\/\/myendoconsult.com\/learn\/wp-content\/uploads\/Turner-syndrome.png 3000w, https:\/\/myendoconsult.com\/learn\/wp-content\/uploads\/Turner-syndrome-300x210.png 300w, https:\/\/myendoconsult.com\/learn\/wp-content\/uploads\/Turner-syndrome-768x538.png 768w, https:\/\/myendoconsult.com\/learn\/wp-content\/uploads\/Turner-syndrome-1536x1075.png 1536w, https:\/\/myendoconsult.com\/learn\/wp-content\/uploads\/Turner-syndrome-2048x1434.png 2048w\" sizes=\"auto, (max-width: 3000px) 100vw, 3000px\" \/><figcaption class=\"wp-element-caption\">Turner Syndrome (Clinical Features and Karyotype Analysis)<\/figcaption><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Pathophysiology<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Short Stature<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Loss of <strong>SHOX gene<\/strong> on the pseudoautosomal region (Xp22) \u2192 deficient osteogenic factor \u2192 short stature, cubitus valgus, short 4th metacarpals.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Gonadal Dysgenesis<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Rudimentary \u201cstreak\u201d gonads \u2192 minimal estrogen \u2192 sexual infantilism, <a href=\"https:\/\/myendoconsult.com\/learn\/evaluation-of-primary-amenorrhea\/\" data-wpil-monitor-id=\"211\">primary amenorrhea<\/a>.<\/li>\n\n\n\n<li>A small subset with mosaicism may have some pubertal development or cyclical menses.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Clinical Features<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Height \/ Body Proportions<\/strong>\n<ul class=\"wp-block-list\">\n<li>Nearly all &lt;5 feet tall if untreated.<\/li>\n\n\n\n<li>May show <strong>increased upper-to-lower body<\/strong> segment ratio (longer torso relative to legs).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Neonatal Findings<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Congenital lymphedema<\/strong> of hands\/feet.<\/li>\n\n\n\n<li><strong>Cutis laxa<\/strong> (excess neck skin).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Skeletal<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Short, webbed neck<\/strong><\/li>\n\n\n\n<li><strong>High-arched palate<\/strong><\/li>\n\n\n\n<li><strong>Shield chest<\/strong> (broad, widely spaced nipples)<\/li>\n\n\n\n<li><strong>Short 4th metacarpals<\/strong><\/li>\n\n\n\n<li><strong>Cubitus valgus<\/strong><\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Facial\/Ear\/Neck<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Micrognathia<\/strong>, \u201cfishmouth\u201d appearance, low-set\/deformed ears, posterior hairline extends down the neck.<\/li>\n\n\n\n<li>Frequent <strong>otitis media<\/strong> (eustachian tube anomalies).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Cardiovascular<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Coarctation of the aorta<\/strong><\/li>\n\n\n\n<li><strong>Bicuspid aortic valve<\/strong>, elongation of transverse aortic arch<\/li>\n\n\n\n<li>Hypertension, risk of <strong>aortic dissection<\/strong><\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Renal<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Horseshoe kidney<\/strong>, ureteropelvic junction anomalies, other structural kidney issues.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Neurocognitive<\/strong>\n<ul class=\"wp-block-list\">\n<li>Intelligence usually normal, but may have learning disabilities (particularly visuospatial, math).<\/li>\n\n\n\n<li>Increased risk of <strong>attention-deficit<\/strong> issues, social cognition deficits (e.g., trouble interpreting facial expressions).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Endocrine \/ Metabolic<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Hypothyroidism<\/strong> (often autoimmune \/ Hashimoto\u2019s).<\/li>\n\n\n\n<li><strong>Glucose intolerance<\/strong>, possible <a href=\"https:\/\/myendoconsult.com\/learn\/diabetes-mellitus\/\" data-wpil-monitor-id=\"212\">diabetes mellitus<\/a>.<\/li>\n\n\n\n<li><strong>Liver enzyme elevations<\/strong>.<\/li>\n\n\n\n<li><strong>Frequent bone fractures<\/strong>, osteoporosis (estrogen deficiency + SHOX haploinsufficiency).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Other<\/strong>\n<ul class=\"wp-block-list\">\n<li>Frequent <strong>keloid formation<\/strong> after surgery.<\/li>\n\n\n\n<li>Pigmented nevi, telangiectasias.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">Gonadal Findings<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Infantile uterus + fallopian tubes<\/strong>.<\/li>\n\n\n\n<li><strong>Streak gonads<\/strong> (fibrous tissue instead of functional ovaries).<\/li>\n\n\n\n<li><a href=\"https:\/\/myendoconsult.com\/learn\/primary-vs-secondary-hypogonadism\/\" data-wpil-monitor-id=\"215\">Primary amenorrhea and lack of secondary<\/a> sex characteristics in most.<\/li>\n\n\n\n<li>Some mosaic variants (45,X\/46,XX) may have partial ovarian function \u2192 variable breast development, possible scant menses, or even normal cycles.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Variants with Y Mosaicism<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>45,X\/46,XY<\/strong> may lead to <strong>mixed gonadal dysgenesis<\/strong> \u2192 ambiguous genitalia, virilization.<\/li>\n\n\n\n<li>If a Y chromosome is present, prophylactic <strong>gonadectomy<\/strong> is recommended due to high risk of gonadoblastoma or dysgerminoma.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Diagnosis<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Clinical suspicion<\/strong>: Short-stature phenotypic female with lack of normal pubertal development and\/or Turner stigmata.<\/li>\n\n\n\n<li><strong>Karyotype<\/strong> (peripheral blood) confirms 45,X or variants.<\/li>\n\n\n\n<li><strong>LH, FSH<\/strong>: Elevated from infancy onward (primary ovarian failure).<\/li>\n\n\n\n<li>Past diagnostic method: Barr body (buccal smear) is now obsolete.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Management<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong><a href=\"https:\/\/myendoconsult.com\/learn\/evaluation-of-adult-growth-hormone-deficiency\/\" data-wpil-monitor-id=\"213\">Growth Hormone<\/a> Therapy<\/strong>\n<ul class=\"wp-block-list\">\n<li>Begun in childhood when height &lt;5th percentile.<\/li>\n\n\n\n<li>Gain of ~2\u20136 inches in final adult height.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Estrogen Replacement<\/strong>\n<ul class=\"wp-block-list\">\n<li>Induce secondary sexual development, optimize bone health, cognitive benefits.<\/li>\n\n\n\n<li>Typically start at ~age 13\u201314 with low-dose estrogen, then increment.<\/li>\n\n\n\n<li>Add <strong>progestin<\/strong> once breakthrough bleeding or full estrogen therapy established to protect endometrium.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Cardiovascular Monitoring<\/strong>\n<ul class=\"wp-block-list\">\n<li>Regular <strong>echocardiography<\/strong> to detect coarctation, aortic root dilation.<\/li>\n\n\n\n<li>Blood pressure monitoring.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Thyroid<\/strong>\n<ul class=\"wp-block-list\">\n<li>Annual <strong>TSH<\/strong> measurement due to hypothyroidism risk.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Fertility<\/strong>\n<ul class=\"wp-block-list\">\n<li>Generally infertile with streak gonads, but some mosaic forms can conceive spontaneously or via assisted reproductive technologies.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Psychosocial Support<\/strong>\n<ul class=\"wp-block-list\">\n<li>Evaluate and manage learning disabilities, social cognition challenges, and psychological well-being.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>TURNER SYNDROME (GONADAL DYSGENESIS) Overview Karyotypes Pathophysiology Clinical Features Gonadal Findings Variants with Y Mosaicism Diagnosis Management<\/p>\n","protected":false},"featured_media":0,"template":"","oen_topic_chapter":[685],"class_list":["post-4422448","oen_topic","type-oen_topic","status-publish","hentry","oen_topic_chapter-reproductive-disorders","post-wrapper","thrv_wrapper"],"_links":{"self":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422448","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic"}],"about":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/types\/oen_topic"}],"version-history":[{"count":4,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422448\/revisions"}],"predecessor-version":[{"id":4423059,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422448\/revisions\/4423059"}],"wp:attachment":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/media?parent=4422448"}],"wp:term":[{"taxonomy":"oen_topic_chapter","embeddable":true,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic_chapter?post=4422448"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}