Turner’s syndrome should be seen by a cardiologist in both the childhood and adult stages. Turner syndrome is also known as congenital ovarian hypoplasia. Humans have 23 pairs of 46 chromosomes, one of which is the sex chromosome. Boys have X and Y chromosomes, and girls have both sex chromosomes as X chromosomes. If a girl has only one X chromosome, or if part of the X chromosome (including the top part of its short arm) is missing, Turner syndrome can occur. Because the X chromosome contains many genes (about 1,000), the loss can cause many problems or even serious problems. 99% of Turner syndrome fetuses are aborted in utero and only 1% of fetuses are born alive. Cardiovascular disease is one of its serious problems. Epidemiological studies show that the mortality rate in Turner syndrome is three times higher than in the normal population, with circulatory diseases accounting for 41% of the mortality (11% ischemic heart disease, 11% cerebrovascular disease, 8% aortic aneurysm, 8% congenital heart disease). The mortality rate in young and middle-aged people with Turner syndrome is 4 to 5 times higher than in the normal population, and it is mainly due to complications of congenital heart disease and coronary artery disease in preterm infants. Its cardiac anomalies are also often a contraindication to assisted pregnancy. What circulatory diseases are children and adults with Turner syndrome susceptible to? Congenital heart disease: Approximately 75% of fetuses and 25% to 45% of girls born alive with Turner syndrome have congenital heart disease. The most common anomalies are bilobed aortic valve (16%) and aortic constriction (11%); however, structural defects such as partial-type pulmonary vein ectopic drainage and atrial and ventricular septal defects are also seen. In the diagnosis of Turner syndrome, imaging should be considered in every patient. In young girls, transthoracic echocardiography is sufficient if a clear image of the cardiac anatomy is available. Otherwise, or when other indications are present, cardiac MRI is recommended, with sedation if necessary. MRI should be done in adolescents and adults. Girls who have already undergone imaging in utero should be reviewed after birth. Aortic coarctation A fatal event that occurs in 1 to 2% of the Turner syndrome population with a preexisting lesion usually the aortic root and/or dilated ascending aorta. The coarctation occurs relatively early, at a median age of 35 years. Magnetic resonance can detect abnormal aortic arch elongation, right subclavian artery malformation, and partial ectopic pulmonary venous return syndrome that are not visualized by echocardiography. Therefore, longitudinal imaging every 5 to 10 years is recommended to assess changes in aortic diameter, even in those patients with a normal initial cardiac examination. Patients should be encouraged to carry a medical alert card and to request an evaluation for aortic coarctation if there is an acute episode of chest pain. Cardiac conduction or repolarization disturbances including prolonged QT intervals have been described and attributed to vegetative dysfunction. Therefore, ECG should be done along with imaging. Hypertension A major risk factor for cardiovascular events is hypertension, which affects 25% of adolescents and 40% to 60% of adults with Turner syndrome. Estradiol deficiency affects conditions related to glucose homeostasis, and early studies have reported changes in glucose homeostasis and the development of diabetes or hypoglycemia in patients with Turner syndrome. Decreased glucose tolerance has been found in both girls and adult women with Turner syndrome, and the incidence of type 2 diabetes is four times higher in Turner syndrome patients than in the normal population (relative risk: 4.4). Women with Turner syndrome are highly susceptible to the comorbidity of certain specific atopic autoimmune diseases, including type 1 diabetes mellitus. These factors are associated with endothelial cell dysfunction, reduced insulin production, abnormal fat metabolism, aggravated centripetal obesity, and early onset of atherosclerosis. Therefore, blood pressure should be measured at each visit and ambulatory blood pressure monitoring should be performed if necessary for a more accurate diagnosis of hypertension and assessment of outcome.