Turner's syndrome is the most common chromosomal abnormality in females, affecting 1:2,500 live female births. It is a result of absence of an X chromosome or the presence of a structurally abnormal X chromosome. Its most consistent clinical features are short stature and ovarian failure. However, it is becoming increasingly evident that adults with Turner's syndrome are also susceptible to a range of disorders, including osteoporosis, hypothyroidism, and renal and gastrointestinal disease. Women with Turner's syndrome have a reduced life expectancy, and recent evidence suggests that this is due to an increased risk of aortic dissection and ischemic heart disease. Up until recently, women with Turner's syndrome did not have access to focused health care, and thus quality of life was reduced in a significant number of women. All adults with Turner's syndrome should therefore be followed up by a multidisciplinary team to improve life expectancy and reduce morbidity.

In this large cohort of women with TS we have shown that the risk of developing autoimmune thyroid disease is particularly high in women with an X-isochromosome, suggesting that a gene on the long arm of the X chromosome (Xq) may play an important pathogenetic role in the development of autoimmune thyroid disease.

Women with Turner's syndrome (TS) have a threefold increase in mortality, primarily as a result of their cardiovascular complications. Recently, the risk of fatal aortic dissection has come to light as a major cause of mortality in women with TS. The aim of this study was to assess the prevalence of aortic root dilatation in a group of women with TS and to investigate the factors contributing to its development. Thirty-eight women with TS attending a dedicated adult Turner clinic were examined clinically and by M-mode and two-dimensional echocardiography on at least one occasion. Aortic root dilatation was defined as an aortic root diameter greater than the 95th centile for body surface area. Fasting serum lipid concentrations were measured in all women. Additionally, 18 subjects underwent noninvasive assessment of central arterial stiffness using applanation tonometry. Fifty percent of subjects were hypertensive and a similar number had an abnormal echocardiogram. A bicuspid aortic valve was present in 33% of subjects, 16 women (42%) had ascending aortic root dilatation. This was associated with a bicuspid aortic valve in four women and hypertension in 11. Two women had isolated aortic root dilatation. Aortic root diameter was significantly associated with systolic blood pressure (r = 0.5, P = 0.003) and left ventricular thickness (r = 0.5, P = 0.02). There was no association with serum lipids or arterial compliance. Structural cardiac abnormalities are present in up to 50% of women with Turner's syndrome. Aortic root dilatation is a significant risk in women with Turner's syndrome and is closely dependent on blood pressure. Aortic root dilatation does not appear to be related to atherosclerosis and is more likely to be due to a mesenchymal defect. Regular surveillance of the aortic root diameter is essential in all women with Turner's syndrome and hypertension should be treated aggressively when present in order to minimize the risk of potentially fatal aortic dissection.

Women with Turner's syndrome may be at increased risk of developing coronary artery disease as a result of the higher frequency of hypertension and obesity. Routine screening of this population for risk factors for ischaemic heart disease is recommended.

Women with Turner's syndrome often have elevated liver enzymes. Oestrogen/progestagen therapy using oestradiol valerate improves liver function in this group of patients. The mechanisms behind this are unclear.