Genetic Disorders
Turner Syndrome
터너증후군
Female phenotype with single X chromosome (45,X) or mosaicism
- How common
- 1 in 2,500 female births
- Typical age
- Females
What is it?
Complete or partial loss of one X chromosome (45,X or 45,X/46,XX mosaic) → SHOX deficiency.
Commonly affected: Female reproductive, skeletal, cardiac, renal, lymphatic
How it develops
- X-chromosome lossMeiotic or mitotic nondisjunction loses X
- SHOX haploinsufficiencyXp22.33 SHOX haploinsufficiency → skeletal anomalies
- Streak gonadOvarian fibrosis with follicle loss
- Clinical manifestationShort stature + primary amenorrhea + cardiac/renal anomalies
Symptoms
- Primary amenorrheaStreak gonads, infertility
- Cardiac anomaliesCoarctation, bicuspid AV (30%)
- Short statureAverage adult height 143 cm
- Webbed neckPterygium colli
- Shield chestBroad chest with widely spaced nipples
How it is examined
- Growth chartHeight <3rd percentile
- KaryotypeConfirm 45,X or mosaic (FISH)
- Echo + renal USCoarctation, horseshoe kidney
Imaging
Bone age + skeletal survey (Madelung deformity, short 4th metacarpal).
- Short 4th metacarpal
- Madelung deformity
Cardiac MRI for coarctation and bicuspid AV.
- Aortic coarctation
- Bicuspid aortic valve
Non-surgical care
- Growth hormoneStart at diagnosis (gain 5–7 cm)
- Estrogen replacementLow-dose at 12–13 → puberty induction
- Cardiovascular monitoringLifelong echo/MRI (aortic dissection risk)
- Osteoporosis preventionVitamin D, calcium, HRT
- Hearing/thyroid screenOM and autoimmune thyroiditis common
Conservative options are generally tried first. Medications listed here can have side effects — discuss them with your prescriber.
When surgery is considered
Aortic coarctation, renal malformations
Procedures that may be discussed
- Coarctation repair
- Donor egg IVF (for pregnancy)
- Lymphedema management
Outlook
Normal life expectancy with treatment. Cardiovascular surveillance is critical.