Pathophysiology of Turner syndrome

Turner syndrome is a symptom complex caused by missing or partially missing X chromosome (45, XO)

Signs and Symptoms

1) lack of secondary sex characteristics

2) infertility 3) streak gonads (gonadal dysgenesis) 4) webbed neck 5) shield-shaped chest 6) low hairline 7) redundant skin folds on back of neck 8) abnormal elbow angle 9) fish mouth 10) epicanthal folds 11) low-set, deformed ears 12) lymphedema 13) renal defects 14) cardiovascular defects (coarctation of aorta, bicuspid aortic valve, and dilated aorta)

Characteristic Test Findings

Laboratory – 1) decreased estrogen 2) decreased estradiol 3) increased FSH 4) increased LH

Associated Conditions

in Turner syndrome there is an increased incidence of – hypertension, autoimmune thyroid disease, glucose intolerance, inflammatory bowel disease, hypoplastic nails, multiple pigmented nevi, hearing loss, cystic hygroma

Inheritance/Epidemiology

affects 1/3000 females; Turner syndrome does not affect males

Treatment

1) at time of puberty, estrogen to promote sexual development 2) combination of growth hormone and oxandrolone to improve short stature

Tips for USMLE

1) if the patient is male, it is not Turner’s syndrome 2) if a 15 year old girl is 4ft 6 inch tall, has no breast budding with widely spaced nipples, and a low hairline, think Turner’s