Turner syndrome is a common chromosomal disorder with only one X-chromosome or partial deletions in one X-chromosome in all or some of the cell-lines in the body. Appr. 18 girls/year are being born with the syndrome in Denmark. The syndrome is mostly known for reduced final height and the lack of pubertal development with infertility, but it is also known for diseases influencing other parts of the body like the heart with the risk of development of aortic dilatation and subsequently dissection with the risk of rupture, profuse bleeding and sudden death. Reduced bone strength and increased risk of bone fracture are also features of the syndrome. Treatment with growth hormone and female sex-hormones are well-established treatments.