FSH may be a useful tool to allow early diagnosis of Turner syndrome.

Background: Ultrasensitive assays to measure pre-pubertal gonadotropins levels could help identify patients with Turner syndrome (TS) in mid-childhood, but studies in this field are scarce. The aim of this study was to analyze gonadotropins levels in girls with TS throughout childhood.
Methods: Retrospective longitudinal study conducted with 15 girls with TS diagnosed with < 5 years whose FSH and LH measures were available since then. Hormones were evaluated in newborn/mini-puberty (< 0.5 years), early childhood (0.5-5 years), mid-childhood (5-10 years) and late childhood/adolescence (> 10 years). In newborn/mini-puberty and late childhood/adolescence pre-pubertal or pubertal gonadotropins were considered normal; in early childhood and mid-childhood concentrations above the pre-pubertal range were considered abnormal.
Results: Abnormally high FSH alone was found in four of five patients in newborn/mini-puberty, 13 of 15 during early childhood and nine of 15 during mid-childhood. In the group of 12 patients in late childhood/adolescence, the three girls with spontaneous puberty had only normal levels; the remaining showed only post-menopausal concentrations. In mid-childhood one patient exhibited only pre-pubertal FSH. Conversely, most LH measurements in early and mid-childhood were normal.
Conclusion: Karyotyping of girls with short stature and high FSH levels would allow early diagnosis of Turner syndrome in a significant number of patients, particularly when resources for chromosome study of all girls with growth deficiency are limited.