Turner Syndrome Flashcards
A 16-year-old girl presents to the clinic for evaluation of delayed puberty. She has not had menarche and reports difficulty keeping up with her peers in height. Physical examination reveals short stature, a webbed neck, widely spaced nipples, and a broad chest. Blood pressure measurement in the right arm is 130/80 mmHg, while in the lower extremities, it is 110/70 mmHg. Her history includes recurrent otitis media and a diagnosis of horseshoe kidney on a prior ultrasound. Laboratory testing shows an elevated follicle-stimulating hormone (FSH) level.
Which of the following is the most appropriate next step in confirming the diagnosis, and what are the key components of long-term management for this patient?
A. Karyotype analysis; estrogen replacement therapy and screening for cardiac anomalies
B. Bone marrow biopsy; growth hormone therapy and renal ultrasound
C. Thyroid antibody testing; androgen replacement therapy and MRI of the brain
D. Serum testosterone level; weight-bearing exercises and surgical correction of the webbed neck
Correct Answer: Karyotype analysis; estrogen replacement therapy and screening for cardiac anomalies
Explanation: This patient presents with classic features of Turner syndrome, including short stature, webbed neck, delayed puberty, and a history of recurrent otitis media. The elevated FSH level reflects ovarian dysgenesis, a hallmark of Turner syndrome. The differential blood pressure between the upper and lower extremities raises suspicion for coarctation of the aorta, a common cardiovascular anomaly in Turner syndrome. Horseshoe kidney, another typical finding, has also been identified. Karyotype analysis is the diagnostic test of choice to confirm the 45,X or mosaic genotype. Long-term management includes estrogen replacement therapy to induce secondary sexual characteristics and prevent osteoporosis. Screening for cardiovascular anomalies, such as coarctation of the aorta and bicuspid aortic valve, is critical, typically via echocardiography or cardiac MRI. Growth hormone therapy may also be considered to enhance height if initiated early.
Incorrect Answers:
B. Bone marrow biopsy: Not indicated, as Turner syndrome is not associated with hematologic abnormalities requiring biopsy. Growth hormone therapy is appropriate, but renal ultrasound has already identified the horseshoe kidney. C. Thyroid antibody testing: Turner syndrome patients are predisposed to autoimmune thyroiditis, but this is not diagnostic. Androgen replacement therapy is not relevant. D. Serum testosterone level: This is not diagnostic of Turner syndrome, and while weight-bearing exercises are beneficial for bone health, surgical correction of a webbed neck is cosmetic and not routinely required.
What is the most common chromosomal abnormality in Turner syndrome?
Turner syndrome is most commonly caused by monosomy X (45,X).
What is the typical genotype found in Turner syndrome?
The typical genotype is 45,X, but variations like mosaicism can also occur.
What other (less common) chromosomal variations can occur in Turner syndrome?
Other chromosomal variations include mosaicism (e.g., 45,X/46,XX) or partial deletion of an X chromosome.
Is Turner syndrome associated with advanced maternal age?
No
What is a hallmark physical feature of Turner syndrome seen on the neck?
Webbed neck is a hallmark feature caused by cystic hygroma during fetal development.
Short posterior hairline.
What are the common thoracic features seen in Turner syndrome?
A broad chest with widely spaced nipples is a common thoracic feature.
What is the common height pattern in Turner syndrome patients?
Patients with Turner syndrome typically have short stature.
What is commonly seen on patient’s hands and arms if they have Turner syndrome?
A shortened fourth metacarpal.
Dysplastic nails.
cubitus valgus (elbow turned inward).
What cardiovascular abnormality is most strongly associated with Turner syndrome?
Coarctation of the aorta is the most strongly associated cardiovascular abnormality:
- Hypertension in upper extremities:
(Elevated blood pressure in the arms compared to the legs) - Weak or delayed femoral pulses:
(Due to reduced blood flow distal to the coarctation) - Claudication or leg pain:
(Especially during exercise, due to reduced perfusion to the lower limbs) - Murmur:
(A systolic murmur heard best at the back or left infrascapular area) - Collateral circulation:
(Development of intercostal artery collaterals, which can cause rib notching on chest X-ray)
What valvular condition is frequently found in Turner syndrome?
Bicuspid aortic valve.
The murmur associated with by bicuspid aortic valve is a systolic ejection click with a crescendo-decrescendo murmur (Aortic stenosis) that is best heard at the right upper sternal border. Progressive calcification and narrowing can lead to symptoms like dyspnea, angina, or syncope in adulthood. Due to leaflet dysfunction, patients may later develop a diastolic decrescendo murmur (aortic regurg).
What is the most dangerous cardiovascular condition associated with Turner syndrome?
aortic root dilation –> aortic dissection
There’s an increased risk of this during pregnancy.
What is given to patients with Turner syndrome to mitigate the cardiovascular manifestations associated with this disease?
Beta blockers.
What is the main endocrine treatment used to initiate puberty in Turner syndrome?
Estrogen replacement therapy (estradiol) is used to initiate puberty (started at 11 years old) and develop secondary sexual characteristics.
What is the purpose of growth hormone therapy in Turner syndrome?
Growth hormone therapy is used to improve final adult height.
