New genomic understanding and challenges in clinical care of Turner syndrome.

Turner syndrome is a sex chromosome abnormality in female individuals characterised by the complete or partial loss of one X chromosome in all or some cells. It is a rare genetic condition occurring in approximately 50 per 100 000 (1 in 2000) female individuals. Turner syndrome is associated with a wide range of clinical characteristics including short stature, hypergonadotropic hypogonadism, ovarian dysgenesis, delayed puberty, infertility, congenital heart disease, endocrine disorders (including autoimmune conditions and type 2 diabetes), hearing problems, and neurocognitive deficits. Morbidity and mortality are increased compared with the general population. Median age at diagnosis is 15 years, delaying appropriate counselling and treatment in many cases. Growth promoting treatment is used during childhood and adolescence, while female sex hormone substitution is recommended from late childhood until at least the average age of menopause. A multidisciplinary approach is essential for optimal care, with the aim of reducing the increased morbidity and mortality and improving quality of life among women with Turner syndrome. We review advances in the clinical characterisation and multiomics of Turner syndrome, which should lead to new insights and inform new treatment strategies for individuals with Turner syndrome.