ESSENTIALS OF DIAGNOSIS
Short stature with normal GH levels.
Primary amenorrhea or early ovarian failure.
Epicanthal folds, webbed neck, short fourth metacarpals.
Renal and cardiovascular anomalies.
Turner syndrome comprises a group of X chromosome disorders that are associated with spontaneous abortion, primary hypogonadism, short stature, and other phenotypic anomalies (Table 26–14). It affects 1–2% of fetuses, of which about 97% abort, accounting for about 10% of all spontaneous abortions. Nevertheless, it affects about 1 in every 2500 live female births. Patients with the classic syndrome (about 50% of cases) lack one of the two X chromosomes (45,XO karyotype). About 12% of patients harbor mosaicism for Y chromosome sequences. Other patients with Turner syndrome have X chromosome abnormalities, such as ring X or Xq (X/abnormal X) or X chromosome deletions affecting all or some somatic cells (mosaicism, XX/XO).
Table 26–14.Manifestations of Turner syndrome. |Favorite Table|Download (.pdf) Table 26–14. Manifestations of Turner syndrome.
Short stature (98%)
Head and neck features
High-arched palate (35%)
Low posterior hairline (40%)
Pterygium colli (webbed neck 40%)
Cataracts, corneal opacities
Epicanthal folds (20%), strabismus (15%), ptosis (10%)
Gonadal dysgenesis (primary amenorrhea 80%) or early ovarian failure (20%)
Skeletal and extremity abnormalities
Broad (shield) chest (30%) with wide-spaced hypoplastic nipples
Cubitus valgus of arms (50%) and knock knees (35%)
Lymphedema of hands and feet (30%)
Madelung wrist deformity (5%)
Short fourth metacarpals (40%)
Conductive hearing loss (30%) and recurrent otitis media (60%)
Low-set and posteriorly rotated ears
Aortic dilation or aneurysm (25% with bicuspid aortic valve)
Bicuspid aortic valve (30%) with aortic stenosis or regurgitation
Coarctation (14%) and cystic medial necrosis of aorta
Hypertension (50%, idiopathic or due to coarctation or kidney disease)
Partial anomalous pulmonary venous return (18%)
Celiac disease (8%)
Hepatic transaminases, elevated (65%)
Inflammatory bowel disease (3%)
Telangiectasias with bleeding
Kidney abnormalities (60%)
Horseshoe kidney (10%), duplication or abnormal positioning of renal pelvis or ureters (15%)
Emotional immaturity (40%)
Learning disabilities and ADHD (40%)
Sensorineural hearing loss
Skin and nail disorders
Autoimmune (Hashimoto) thyroiditis (37%)
Diabetes mellitus (10%) or glucose intolerance (35%)
1. CLASSIC TURNER SYNDROME (45,XO GONADAL DYSGENESIS)
Features of Turner syndrome are variable and may be subtle in girls with mosaicism. Turner syndrome may be diagnosed in infant girls at birth, since they tend to be small and may exhibit severe lymphedema. Evaluation for childhood short stature often leads to the diagnosis. Girls and women with Turner syndrome have an increased risk of aortic coarctation and bicuspid aortic valves; these cardiac abnormalities are more common ...