Overview
Turner syndrome (also known as 45,X syndrome, Ullrich-Turner syndrome, or gonadal dysgenesis, 45,X) is a chromosomal condition that affects females, caused by complete or partial absence of one X chromosome. The most common karyotype is 45,X (monosomy X), though mosaic forms (e.g., 45,X/46,XX) and structural abnormalities of the X chromosome (such as isochromosome Xq, ring X, or deletions) also occur. Turner syndrome affects multiple body systems, including the reproductive, cardiovascular, skeletal, renal, and endocrine systems. Key clinical features include short stature, ovarian insufficiency leading to delayed puberty and infertility, congenital heart defects (particularly bicuspid aortic valve and coarctation of the aorta), lymphedema (especially in neonates), a broad or webbed neck, low posterior hairline, shield chest with widely spaced nipples, and renal anomalies such as horseshoe kidney. Girls and women with Turner syndrome are also at increased risk for autoimmune thyroid disease (Hashimoto thyroiditis), type 2 diabetes, hearing loss (both sensorineural and conductive), osteoporosis, and learning difficulties particularly involving visuospatial and mathematical skills, though intelligence is typically in the normal range. Cardiovascular complications, including aortic dissection and hypertension, are a leading cause of morbidity and mortality and require lifelong surveillance. Treatment is multidisciplinary and tailored to the individual's specific manifestations. Growth hormone therapy is standard for improving final adult height and is typically initiated in early childhood. Estrogen replacement therapy is used to induce puberty and maintain secondary sexual characteristics, followed by combined estrogen-progesterone therapy for uterine health. Regular cardiac imaging, thyroid function monitoring, hearing assessments, and bone density evaluations are essential components of ongoing care. Assisted reproductive technologies, including oocyte donation, may be considered for fertility, though pregnancy carries increased cardiovascular risks requiring careful evaluation. With appropriate medical management and surveillance, most individuals with Turner syndrome lead full and productive lives.
Also known as:
Clinical phenotype terms— hover any for plain English:
Sporadic
Usually appears on its own, not inherited from a parent
Neonatal
Begins at or shortly after birth (first 4 weeks)
FDA & Trial Timeline
10 eventsEunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
Universiti Kebangsaan Malaysia Medical Centre — PHASE2
Ascendis Pharma A/S — PHASE3
University Hospital, Strasbourg, France
Rhythm Pharmaceuticals, Inc. — PHASE2
Rhythm Pharmaceuticals, Inc. — PHASE3
Children's Mercy Hospital Kansas City — PHASE4
Central Hospital, Nancy, France
Gødstrup Hospital
IRCCS Azienda Ospedaliero-Universitaria di Bologna
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
No FDA-approved treatments are currently listed for Turner syndrome.
20 clinical trialsare actively recruiting — trials can provide access to cutting-edge therapies.
View clinical trials →Rare Disease Specialist
Treatment Centers
8 centersCHU Angers
📍 Angers
👤 Julien Rossignol, Dr
CHU Nantes
📍 Nantes
👤 Sebastien HASCOËT
Stanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
Travel Grants
No travel grants are currently matched to Turner syndrome.
Community
No community posts yet. Be the first to share your experience with Turner syndrome.
Start the conversation →Latest news about Turner syndrome
1 articlesCaregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Common questions about Turner syndrome
What is Turner syndrome?
Turner syndrome (also known as 45,X syndrome, Ullrich-Turner syndrome, or gonadal dysgenesis, 45,X) is a chromosomal condition that affects females, caused by complete or partial absence of one X chromosome. The most common karyotype is 45,X (monosomy X), though mosaic forms (e.g., 45,X/46,XX) and structural abnormalities of the X chromosome (such as isochromosome Xq, ring X, or deletions) also occur. Turner syndrome affects multiple body systems, including the reproductive, cardiovascular, skeletal, renal, and endocrine systems. Key clinical features include short stature, ovarian insufficien
How is Turner syndrome inherited?
Turner syndrome follows a sporadic inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Turner syndrome typically begin?
Typical onset of Turner syndrome is neonatal. Age of onset can vary across affected individuals.
Are there clinical trials for Turner syndrome?
Yes — 20 recruiting clinical trials are currently listed for Turner syndrome on UniteRare. See the clinical trials section on this page for phase, sponsor, and site details sourced from ClinicalTrials.gov.
Which specialists treat Turner syndrome?
25 specialists and care centers treating Turner syndrome are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.