Turner syndrome and clinical treatment

Background: Turner syndrome (TS) is a genetic disorder associated with abnormalities of the X chromosome, occurring in about 50 per 100 000 liveborn girls. TS is usually associated with reduced adult height, gonadal dysgenesis and thus insufficient circulating levels of female sex steroids leading to premature ovarian failure and infertility. The average intellectual performance is within the normal range. New insight into genetics, epidemiology, cardiology, endocrinology and metabolism from a number of recent studies will be included in this review. Sources of data: For this review we concentrated on all papers published on TS with special emphasis on the most recent literature. Also papers relating to cardiology, especially aortic dissection, paediatrics and the effects of estradiol in other conditions were considered. The main source was PubMed and the major endocrinology and cardiology journals. Areas of agreement: Treatment with growth hormone (GH) during childhood and adolescence allows a considerable gain in adult height. SHOX deficiency explains some of the phenotypic characteristics in TS, principally short stature. Puberty has to be induced in most cases, and female sex hormone replacement therapy (HRT) is given during adult years. Morbidity and mortality is increased, especially due to the risk of dissection of the aorta and other cardiovascular (CV) diseases, as well as the risk of type 2 diabetes, osteoporosis and thyroid disease. Areas of controversy: The proper dose of HRT with female sex steroids has not been established, and, likewise, benefits and/or drawbacks from HRT have not been thoroughly evaluated. In most countries it seems that the transition period from paediatric to adult care is especially vulnerable and the proper framework for transition has not been established. Today, most treatment recommendations are based on expert opinion and are unfortunately not evidence based, although more areas, such as GH treatment for increasing height, are well founded. Growing points: The description of adult life with TS has been broadened and medical, social and psychological aspects are being added at a compelling pace. Areas timely for developing research: Proper care during adulthood should be studied, since most morbidity potentially is amenable to proper care. Especially, interventional strategy and follow-up with respect to congenital CV malformations, as well as secondary CV disease, have to be developed and new treatment algorithms have to be studied. In summary, TS is a condition associated with a number of diseases and conditions, which need the attention of a multi-disciplinary team.