Hormone replacement therapy in Turner syndrome is important—a new meta-analysis points at many shortcomings in the available literature

Excerpt

Turner syndrome (TS) can by most standards be viewed as a rare condition, although it is one of the more common rare conditions. As in all rare conditions, it is difficult to accumulate sufficient data to base treatment and care on evidence and therefore many aspects of TS is based on expert opinion. And since ovarian dysgenesis is almost inevitable early in the lives of most females with TS, estrogen replacement therapy (ERT) is cornerstone to appropriate treatment of TS, to induce puberty and uphold female sex characteristics, maintain bone mass, body composition, and possibly to avoid undue cardiovascular morbidity and positively impact neurocognitive development. However, hard endpoints are not available within the realm of TS research and much has been extrapolated from the literature concerning the effects of ERT in the postmenopausal setting. And such extrapolation may not be valid. Just considering the lengthy discussions concerning the WHI study and the possibility that the timing hypothesis for ERT exists and that the timing of start with ERT may therefore be of great importance [1]. In addition ascertainment bias is a problem in TS research, since less than two-thirds of all TS are ever diagnosed [2], decreasing the validity of clinical studies of TS. …