II. Epidemiology

  1. Incidence: 1 in 3000 live female births

III. Pathophysiology

  1. Partial or complete absence of one X-Chromosome
    1. Karyotype: 45,X
    2. Results in X-Chromosome genes that fail inactivation
      1. Expression of these genes causes Turner Phenotype
  2. Ovarian sex hormone deficiency
    1. Due to congenitally fibrotic ovaries
    2. Results in lack of spontaneous pubertal development
  3. High spontanous Miscarriage rate
    1. Karyotype 45,X associated with 99% Miscarriage rate
    2. Turner's causes 10% of first trimester abortions
    3. No known risk factors and recurrence is rare

V. Signs: Fetus and infant

VI. Signs: Teen and older

  1. Majority of patients
    1. Short Stature
    2. Infantile female genitalia and Breasts
  2. More than 50% of patients have:
    1. High arched, narrow Palate with crowded teeth
    2. Eyelid Ptosis and infraorbital creases
    3. Webbed Neck
    4. Shield (broad) chest with widely spaced nipples
    5. Delayed Growth of axillary and pubic hair
    6. Hyperconvex nails
    7. Deformed or rotated ears
    8. Cubitus valgus
    9. Short Metacarpals (especially fourth)
    10. Congenital Lymphedema involving arms and legs
    11. Increased pigmented nevi
    12. Low posterior hairline

VII. Associated Conditions

  1. Cardiac malformation (33% of patients)
    1. Aortic Coarctation
    2. Bicuspid aortic valve
    3. Hypertension
  2. Strabismus
  3. Sensorineural Hearing Loss
  4. Recurrent Otitis Media
  5. Renal malformations (e.g. horseshoe Kidney)
  6. Autoimmune Thyroiditis
  7. Celiac Disease
  8. Congenital Hip Dysplasia
  9. Scoliosis

VIII. Labs

  1. Initial
    1. Karyotype
      1. Missing X Chromosome (45,X) in 50% of cases
    2. Follicle Stimulating Hormone
      1. Abnormally increased by age 14 years
    3. Buccal mucosa smear (historical interest only)
      1. Negative sex chromatin (male pattern)
  2. Annual
    1. Thyroid Stimulating Hormone (TSH)
    2. Liver Function Tests
    3. Fasting lipid profile
    4. Fasting Serum Glucose
  3. Other
    1. Tissue transglutaminase IgA (celiac) q2-4 years

IX. Imaging

  1. Chest XRay (initially)
    1. Aortic Coarctation
    2. Osteoporosis
  2. Echocardiogram
    1. Obtain initially at diagnosis
    2. Repeat q5-10 years to evaluate aortic root dilatation
  3. DEXA Scan
    1. Obtain baseline in adulthood
    2. Repeat periodically

X. Management: Children and Teens

  1. Genetic Consultation
  2. Congenital Heart Disease
    1. Initial Echocardiogram and Chest XRay
    2. Initial Blood Pressures in all 4 extremities
    3. Monitor and treat as needed
  3. Linear growth delay
    1. Consider Growth Hormone from age 1-2 to age 14
  4. Estrogen therapy
    1. Start in preteen years
    2. Promotes Sexual Development
    3. Prevents Osteoporosis
  5. Hearing evaluation
    1. Audiometry initially and monitoring periodically
  6. Vision evaluation
    1. Refer to pediatric ophthalmology after age 1
    2. Evaluate for Strabismus and Hyperopia
  7. Musculoskeletal evaluation
    1. Barlow and Ortolani Testing for hip dysplasia
    2. Evaluate for Scoliosis and kyphosis in teens
  8. Genitourinary evaluation
    1. Renal Ultrasound to assess for anomalies
  9. Dental evaluation
    1. Orthodontist evaluation for malocclusion

XI. Management: Women

  1. Fertility and Sexual Development
    1. Consult with gynecologic specialists
  2. Manage comorbid Coronary Risk Factors
  3. Osteoporosis Prevention
    1. Calcium and Vitamin D supplementation

XII. References

  1. Behrman (2000) Nelson Pediatrics, Saunders, p. 1753-4
  2. Wilson (1998) Williams Endocrinology, p. 1337-52
  3. Morgan (2007) Am Fam Physician 76:405-10 [PubMed]
  4. Saenger (2001) J Clin Endocrinol Metab 86(7):3061-9 [PubMed]

Images: Related links to external sites (from Bing)

Related Studies (from Trip Database) Open in New Window

Ontology: Turner Syndrome (C0041408)

Definition (MSH) A syndrome of defective gonadal development in phenotypic females associated with the karyotype 45,X (or 45,XO). Patients generally are of short stature with undifferentiated GONADS (streak gonads), SEXUAL INFANTILISM, HYPOGONADISM, webbing of the neck, cubitus valgus, elevated GONADOTROPINS, decreased ESTRADIOL level in blood, and CONGENITAL HEART DEFECTS. NOONAN SYNDROME (also called Pseudo-Turner Syndrome and Male Turner Syndrome) resembles this disorder; however, it occurs in males and females with a normal karyotype and is inherited as an autosomal dominant.
Definition (CHV) genetic disease that produces sterile females due to the X chromosome defect
Definition (CHV) genetic disease that produces sterile females due to the X chromosome defect
Definition (CHV) genetic disease that produces sterile females due to the X chromosome defect
Definition (CHV) genetic disease that produces sterile females due to the X chromosome defect
Definition (CHV) genetic disease that produces sterile females due to the X chromosome defect
Definition (MEDLINEPLUS)

Turner syndrome is a genetic disorder that affects a girl's development. The cause is a missing or incomplete X chromosome. Girls who have it are short, and their ovaries don't work properly.

Other physical features typical of Turner syndrome are

  • Short, "webbed" neck with folds of skin from tops of shoulders to sides of neck
  • Low hairline in the back
  • Low-set ears
  • Swollen hands and feet

Most women with Turner syndrome are infertile. They are at risk for health difficulties such as high blood pressure, kidney problems, diabetes, cataracts, osteoporosis, and thyroid problems.

Doctors diagnose Turner syndrome based on symptoms and a genetic test. Sometimes it is found in prenatal testing. There is no cure for Turner syndrome, but there are some treatments for the symptoms. Growth hormone often helps girls reach heights that are close to average. Hormone replacement can help start sexual development. Assisted reproduction techniques can help some women with Turner syndrome get pregnant.

NIH: National Institute of Child Health and Human Development

Definition (NCI) A gonadal dysgenesis syndrome occurring in phenotypic females, characterized by the absence of a part or all of one of the sex chromosomes. Signs and symptoms include short stature, webbing of neck, low-set ears, hypogonadism, and sterility.
Definition (NCI) A gonadal dysgenesis syndrome occurring in phenotypic females, characterized by the complete absence of one of the sex chromosomes. Signs and symptoms include short stature and hypogonadism.
Definition (CSP) genetic disease that produces sterile females due to monosomy for X chromosome; the ovaries are rudimentary or missing; other abnormalities include short stature, webbed neck, and a broad chest with widely spaced nipples.
Concepts Congenital Abnormality (T019) , Disease or Syndrome (T047)
MSH D014424
ICD10 Q96 , Q96.0, Q96.9
SnomedCT 268356004, 205685008, 157020008, 268299006, 205691005, 38804009
English Turner's Syndrome, TURNER'S SYNDROME, Turner's syndrome NOS, Karyotype 45,X, Turner's syndrome, unspecified, monosomy X syndrome, Turner's syndrome (diagnosis), XO genotype, Turner Syndrome, Turner Syndrome (XO Syndrome), XO Syndrome, Turner Syndrome [Disease/Finding], gonadal dysgenesis, xo syndrome, bonnevie-ullrich syndrome, turner's syndrome, gonadal dysgenesis syndrome, Syndrome, Ullrich-Turner, Ullrich Turner Syndrome, Ullrich-Turner Syndrome, Turner syndrome karyotype 45, X, Turner syndrome karyotype 45, X (diagnosis), turner syndrome (xo) karyotype 45, x, Primary ovarian insufficiency, Gonadal dysgenesis - Turner, Karyotype 45, X (disorder), Turner's syndrome NOS (disorder), Pterygolymphangiectasia syndrome, XO syndrome, Turner's syndrome, 45, X syndrome, Karyotype 45, X, TS - Turner's syndrome, X0 - Turner's syndrome, 45X0 - Turner's syndrome, Turner syndrome, Turner syndrome (disorder), chromosome; anomaly, sex, Turner, Morgagni-Turner, Turner-Ullrich, Turner; sex chromosome abnormality, Turner; syndrome, X; monosomy, karyotype; 45,X, monosomy; X, syndrome; Turner, anomaly; chromosomes, chromosomal, sex, Turner, Turner syndrome, NOS, Turners Syndrome, Monosomy X, turner syndrome
Portuguese SINDROME DE TURNER, Genótipo XO, Síndrome de Turner
Spanish SINDROME DE TURNER, Genotipo XO, síndrome de Turner, SAI, síndrome de Turner, SAI (trastorno), síndrome 45, X, síndrome de Turner (trastorno), síndrome de Turner, síndrome de XO, síndrome de pterigolinfangiectasia, Síndrome de Turner
Dutch XO genotype, Turner; geslachtschromosoomafwijking, Turner; syndroom, X; monosomie, anomalie; chromosomen, chromosomaal, geslacht, Turner, chromosoom; anomalie, geslacht, Turner, karyotype; 45,X, monosomie; X, syndroom; Turner, Karyotype 45,X, Syndroom van Turner, niet gespecificeerd, syndroom van Turner, Syndroom van Turner, Turner, syndroom van
French Génotype XO, SYNDROME DE TURNER, Syndrome de Turner
German XO-Genotyp, Karyotyp 45,X, TURNER SYNDROM, Turner-Syndrom, nicht naeher bezeichnet, Turner Syndrom, Albright-Turner-Syndrom, Infantilismus, pterygogonadaler, Turner-Syndrom, Ullrich-Turner-Syndrom, Zwergwuchs, ovarieller
Italian Genotipo XO, Sindrome di Ullrich-Turner, Sindrome di Turner
Japanese XO遺伝子型, ターナーショウコウグン, XOイデンシガタ, 性器発育異常-45X, XO性器発育異常, 45X性器発育異常, 性器発育異常-XO, ターナー症候群, 女子性腺発育障害症候群, 性腺発育障害症候群, Bonnevie-Ullrich症候群, Turner症候群
Swedish Turners syndrom
Czech Turnerův syndrom, XO genotyp
Finnish Turnerin oireyhtymä
Russian DISGENEZIIA GONAD, 45, X, TERNERA SINDROM, DISGENEZIIA GONAD, 45, XO, ДИСГЕНЕЗИЯ ГОНАД, 45, XO, ДИСГЕНЕЗИЯ ГОНАД, 45, X, ТЕРНЕРА СИНДРОМ
Korean 상세불명의 터너 증후군, 터너 증후군, 핵형 45, X
Croatian TURNEROV SINDROM
Polish Zespół Turnera, Dyzgenezja gonad 45X, Dyzgenezja gonad X0
Hungarian Xo genotípus, Turner-syndroma
Norwegian Turners syndrom, Turner-syndrom