Review Question - QID 106530

This patient has a 45,XO karyotype consistent with a diagnosis of Turner syndrome. These patients are at greater risk for congenital cardiac issues, including coarctation of the aorta.

Turner syndrome is characterized by the absence of one sex X chromosome, resulting in a 45,XO karyotype. Amenorrhea, infertility, and "streak" ovaries (aplasia yielding functionless ovarian tissue) are common in these patients. These "streak" ovaries lead to a decreased estrogen level, which is responsible for the short stature, infertility, amenorrhea, and osteoporosis commonly seen in these patients. Additional characteristics include short stature, webbed neck, and a low hairline. There are also numerous associated medical comorbidities, including coarctation of the aorta, horseshoe kidneys, diabetes, thyroid dysfunction, lymphedema, hearing loss, and "streak" ovaries.

Morgan discusses the diagnosis and management of Turner syndrome. Congenital heart defects associated with Turner syndrome include: coarctation of the aorta, bicuspid aortic valve, aortic root dilatation, and aortic dissection. Additional associations include: lymphedema, sensorineural hearing loss, diabetes, and obesity. The diagnosis of Turner syndrome should be considered in all female patients with extremely short stature or primary amenorrhea.

Ross et al. evaluate the outcomes of Turner syndrome patients treated with growth hormone and low-dose estrogen replacement. They find that growth hormone therapy leads to increased adult height in these patients. In addition, low dose ethinyl-estradiol in combination with growth hormone exhibits a synergistic response, with increased patient growth compared to those Turner syndrome patients treated with just growth hormone alone.

Figure A shows the 45,XO karyotype characteristic of Turner syndrome. Illustration A summarizes the constellation of findings commonly associated with Turner syndrome. Illustration B depicts the pathoanatomy seen in coarctation of the aorta. Illustration C shows a CT scan of a horseshoe kidney malformation; this finding is often asymptomatic.

Incorrect Answers:
Answer 1: Turner syndrome is characterized by amenorrhea with a uterus present; "streak" ovaries are a common finding contributing to the infertility and amenorrhea observed in these patients.
Answer 3: Polycystic kidney disease is not associated with Turner syndrome; however, a horseshoe kidney is commonly associated with the condition.
Answer 4: Turner syndrome patients have short stature and webbed necks.
Answer 5: "Elfin" facies is associated with Williams syndrome; Turner syndrome patients commonly have a low posterior hairline and low-set ears.