Gonadotropin secretion in girls with turner syndrome measured by an ultrasensitive immunochemiluminometric assay.
OBJECTIVE
Gonadotropin levels measured by radioimmunoassays are high in girls with Turner syndrome (TS), but overlap significantly with those of normal girls. We hypothesized that gonadotropin levels would be above the normal range in TS when measured by ultrasensitive assays.


METHODS
Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels were measured in 68 TS, and 133 control girls using ultrasensitive immunochemiluminometric assays (ICMA).


RESULTS
FSH levels in TS and normal girls were highest in early childhood (56.0 +/- 39.7 and 2.3 +/- 1.8 IU/l, respectively), declined at 6-10 years of age (11.3 +/- 13.1 and 1.8 +/- 0.9 IU/l, respectively), and then increased again (104.4 +/- 68.9 and 4.9 +/- 2.4 IU/l, respectively). FSH was in the normal range on 11 of 27 occasions in TS girls with ages 5-10 years, and on 3 of 44 occasions in >10 years. Although average LH values were higher than those of controls, they often overlapped the normal range.


CONCLUSIONS
A significant number of TS girls have normal gonadotropins by ICMA. Spontaneous gonadotropin levels are not an adequate screening test for the diagnosis of TS but may prove useful for predicting the gonadal function and determining the appropriate timing of estrogen replacement therapy.
Department of Pediatrics, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7039, USA.
Dionisios
D
Chrysis
Bessie E
BE
Spiliotis
Mark
M
Stene
Emanuele
E
Cacciari
Marsha L
ML
Davenport
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007223:Infant; D008163:Luminescent Measurements; D007986:Luteinizing Hormone / Q000097:blood*; D014424:Turner Syndrome / Q000097:blood*
D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone