Epidemiological, endocrine and metabolic features in Turner syndrome.

Turner syndrome is one of the more common genetic disorders, associated with abnormalities of the X chromosome, and occurring in about 50 per 100 000 liveborn girls. Turner syndrome is usually associated with reduced adult height, gonadal dysgenesis and thus insufficient circulating levels of female sex steroids, and infertility. A number of other signs and symptoms are seen more frequently with the syndrome. Morbidity and mortality are increased. The average intellectual performance is within the normal range. A number of recent studies have provided new insights with respect to epidemiology, cardiology, endocrinology and metabolism. Treatment with GH during childhood and adolescence allows a considerable gain in adult height, although very-long-term consequences of this treatment are not clear. Puberty has to be induced in most cases, and female sex hormone replacement therapy is given during the adult years. The proper dose of hormone replacement therapy (HRT) has not been established, and, likewise, benefits and/or drawbacks from HRT have not been thoroughly evaluated. Since the risk of cardiovascular and endocrinological disease is clearly elevated, proper care during adulthood is emphasized. In summary, Turner syndrome is a condition associated with a number of diseases and conditions which are reviewed in the present paper.