What should be periodically monitored in patients with Turner Syndrome?

Periodic Monitoring for Turner Syndrome Patients

Patients with Turner syndrome require lifelong cardiovascular surveillance with imaging intervals determined by aortic size index (ASI) and risk factors, along with annual monitoring of blood pressure, thyroid function, glucose metabolism, and hearing. 1

Cardiovascular Surveillance

Initial Evaluation at Diagnosis

• Perform both transthoracic echocardiography (TTE) and cardiac MRI at diagnosis to evaluate for bicuspid aortic valve (present in 15-30%), aortic coarctation (7-18%), aortic root/ascending aortic dilation (33%), and other congenital heart defects. 1, 2
• TTE alone is insufficient because the mid-ascending aorta requires cardiac MRI or CT for adequate visualization. 2

Aortic Surveillance Protocol Based on Risk Stratification

For patients ≥15 years old, calculate the ASI (maximal aortic diameter in cm ÷ body surface area in m²) to assess dissection risk, as absolute aortic diameters systematically underestimate risk due to short stature in Turner syndrome. 1, 2

For children <15 years old, use Turner syndrome-specific z-scores rather than ASI to assess aortic dilation. 1

Low-Risk Patients (No Risk Factors)

• Children: TTE or MRI every 5 years 1
• Adults: TTE or MRI every 10 years 1
• Before planned pregnancy: mandatory imaging 1

Intermediate-Risk Patients (ASI ≤2.3 cm/m² with risk factors)

• TTE or MRI every 2-3 years if ASI is stable 1
• Risk factors include: bicuspid aortic valve, aortic coarctation, hypertension, or aortic dilation 1

High-Risk Patients (ASI >2.3 cm/m²)

• At least annual surveillance imaging is required 1, 2
• As ASI approaches 2.5 cm/m², increase imaging frequency based on aortic growth rate, severity of hypertension, and aortic valve function 1

Critical Thresholds

• ASI >2.0 cm/m² is abnormal 1
• ASI ≥2.5 cm/m² with risk factors warrants surgical consultation for prophylactic aortic root/ascending aorta replacement 1, 2
• In obese or very thin patients ≥15 years old, an absolute aortic diameter >4.0 cm may be more accurate than ASI alone for risk assessment 1

Blood Pressure Monitoring

• Monitor blood pressure annually at minimum in all Turner syndrome patients 1
• Treat hypertension aggressively as it is a major modifiable risk factor for aortic dissection 1, 2
• Consider beta-blockers and/or ARBs to potentially inhibit aortic growth 2, 3
• In hypertensive patients requiring hormone replacement, transdermal estradiol is the preferred delivery method 1

Endocrine Monitoring

Thyroid Function

• Screen for hypothyroidism at diagnosis and monitor regularly (at least annually) 1, 3, 4
• Autoimmune hypothyroidism is particularly common in X-isochromosome phenotypes during the first and second decades 5

Glucose Metabolism

• Monitor fasting plasma glucose and HbA1c annually 1
• Type 2 diabetes occurs with higher frequency in Turner syndrome due to haploinsufficiency of Xp genes and β-cell autoimmunity 5

Lipid Profile

• Assess lipid profile at diagnosis and monitor annually 1

Additional Surveillance

Hearing

• Monitor hearing function throughout the lifespan 4

Bone Health

• Monitor for osteoporosis, which occurs in up to 60% of patients 5
• Adequate estrogen replacement is critical for bone health 4

Weight and Lifestyle Factors

• Monitor weight and smoking status annually 1
• Counsel on modifiable cardiovascular risk factors including smoking cessation, regular weight-bearing exercise, and healthy weight maintenance 1

Pregnancy Considerations

• Mandatory thorough cardiovascular evaluation before attempting pregnancy due to substantial aortic dissection risk, especially with pre-existing bicuspid aortic valve or aortic abnormalities 2, 3, 6
• Extensive pre-conception counseling is necessary 2, 3

Common Pitfalls to Avoid

• Never use absolute aortic diameters alone without indexing to body size in patients ≥15 years old, as this systematically underestimates dissection risk 1, 2, 6
• Do not rely solely on TTE for aortic assessment; cardiac MRI or CT is essential for complete visualization 2
• Do not use general population normative data for aortic measurements in children <15 years old; Turner syndrome-specific z-scores are required 1, 3