Turner Syndrome (Monosomy X, Gonadal Dysgenesis)

Key Features

• Webbed neck, triangular facies, short stature, wide-set nipples, amenorrhea, and absence of secondary sex characteristics

• Associated with coarctation of the aorta and genitourinary malformations

• IQ is usually normal but learning disabilities are common

• Mosaic individuals may manifest only short stature and amenorrhea

• Incidence is 1 per 10,000 females

• An estimated 95% of conceptuses with monosomy X are miscarried and only 5% are liveborn

Clinical Findings

• Newborns may have webbed neck, edema of the hands and feet, coarctation of the aorta, and characteristic triangular facies

• Other findings in older girls may include

  • Short stature

  • Shield chest with wide-set nipples

  • Streak ovaries

  • Amenorrhea

  • Absence of secondary sex characteristics

  • Infertility

• Some affected girls, particularly those with mosaicism, have only short stature and amenorrhea, without dysmorphic features

Diagnosis

• Prenatal ultrasonography and chromosome analysis are indicated for the offspring of females with sex chromosome abnormalities

Treatment

• Academic supports for learning issues

• Hormonal treatment includes estrogen therapy, which permits development of secondary sex characteristics and normal menstruation, and prevents osteoporosis

• Growth hormone therapy is also used to increase the height of affected girls