Turner Syndrome (Gonadal Dysgenesis)

Key Features

• Short stature with normal growth hormone levels

• Primary amenorrhea or early ovarian failure

• Epicanthal folds, webbed neck, short fourth metacarpals

• Renal and cardiovascular anomalies

• Incidence: 1 in 2500 live female births

• Diagnosis suspected: at birth, small newborns, often with lymphedema; in childhood, short stature

Clinical Findings

• Features variable and may be subtle if mosaicism

• Short stature

• Webbed neck

• High-arched palate

• Short fourth metacarpals

• Wide-spaced nipples

• Hypertension

• Kidney abnormalities

• Coarctation of aorta

• Hypogonadism presents as delayed adolescence (80%) or early ovarian failure (20%)

• Adults with Turner syndrome have a high incidence of ECG abnormalities

• Emotional disorders

Diagnosis

• Serum FSH and LH levels elevated

• Karyotype shows 45, XO (or X chromosome abnormalities, or mosaicism)

• Serum growth hormone and IGF-I levels normal

• Yearly physical examinations and periodic thyroid, lipid, and glucose testing recommended

Treatment

• Annual surveillance should include

  • Blood pressure determination

  • Laboratory evaluations, including a serum TSH, liver enzymes, BUN, creatinine, and fasting serum lipids and glucose

• Celiac disease screening (serum TTG IgA Ab) is warranted every 2–5 years for school-age girls and then whenever indicated clinically

• Audiology exams are recommended every 1–5 years

• Bone mineral densitometries should be measured periodically for women over age 18 years

• Patients with aortic root enlargement are usually treated with β-blockade and serial imaging

• During pregnancy, women with Turner syndrome have a 2% risk of aortic dissection or rupture, so they require close monitoring with repeated echocardiography