EXPLANATION


The karyotype 45 XO is consistent with a diagnosis of Turner Syndrome (TS), which occurs in approximately 1 in 2500 live born females. Characteristic clinical features include a webbed neck, short stature, and lymphedema of the hands and feet. Cardiovascular disease is the major cause of death in TS. Congenital heart defects are found in about 50% of individuals with TS, consisting mostly of left-sided lesions. The most common cardiac abnormality is a bicuspid aortic valve (15% - 30% of cases), followed by coarctation of the aorta (7% - 18%). A recent American Heart Association Scientific Statement (1) has recommended that the presence of a bicuspid aortic valve or a left-sided obstructive lesion in a female patient should prompt a genetic evaluation of TS. Other less common but well recognized congenital cardiac defects associated with TS include partial anomalous pulmonary venous connection and hypoplastic left heart syndrome (HLHS). Coronary abnormalities are also common, particularly absent left main coronary. These are important to identify as they may have surgical implications.


Turner Syndrome patients are at increased risk of aortic dissection at six times the rate as compared to the general population. Therefore, they require regular follow-up and serial imaging of the aorta, in addition to monitoring and treatment of hypertension.


The most common cardiac surgical procedures performed in TS patients are coarctation repair and aortic arch reconstruction. Due to lymphatic dysfunction, TS patients have a higher incidence of chylothorax and increased length of stay in the intensive care unit.


TS patients with HLHS have a higher incidence of poor outcomes, though they have improved in the most recent era. Due to the increased mortality after the Stage I/Norwood procedure, some centers are more likely to refer TS patients for primary cardiac transplantation as there is evidence of better clinical outcomes.


Truncus arteriosus and other cono-truncal abnormalities are frequently associated with chromosome 22q11 deletion syndrome.


Supravalvar aortic stenosis is a feature of Williams syndrome.


REFERENCES


1. Silberbach M, Roos-Hesselink JW, Andersen NH et al. Cardiovascular Health in Turner Syndrome. A scientific statement from the American Heart Association. Circ Genom Precis Med . 2018; 11(10): e000048. https://doi.org/10.1161/HCG.0000000000000048


2. Chew JD, Hill KD, Jacobs ML, et al. Congenital heart surgery outcomes in Turner Syndrome: The Society of Thoracic Surgeons Database Analysis. Ann Thorac Surg .2019;108:1430-1438.


3. Philip J, Gupta D, Bleiweis MS, Pietra BA, Vyas HV. Hypoplastic left heart in Turner’s syndrome: a primary indication for transplant. Card Young . 2018; 28:458-460


4. Chew JD, Soslow JH, Hall M, et al. Heart transplantation in children with Turner syndrome: Analysis of a linked dataset. Ped Cardiol . 2018; 39:610-616.