Prepubertal Girls With Turner Syndrome and Children With Isolated SHOX Deficiency Have Similar Bone Geometry at the Radius

Authors	SOUCEK O. ZAPLETALOVA J. ZEMKOVA D. SNAJDEROVA M. NOVOTNÁ Dana HIRSCHFELDOVA K. PLASILOVA I. KOLOUSKOVA S. ROCEK M. HLAVKA Z. LEBL J. SUMNIK Z.
Year of publication	2013
Type	Article in Periodical
Magazine / Source	JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM
MU Faculty or unit	Faculty of Medicine
Citation
Doi	http://dx.doi.org/10.1210/jc.2013-1113
Field	Endocrinology, diabetology, metabolism, nutrition
Keywords	LERI-WEILL DYSCHONDROSTEOSIS; IDIOPATHIC SHORT STATURE; QUANTITATIVE COMPUTED-TOMOGRAPHY; X-RAY ABSORPTIOMETRY; MINERAL DENSITY; GENE SHOX; PROXIMAL RADIUS; GROWTH FAILURE; PREVALENCE; FRACTURES
Description	Context: The low bone mineral density (BMD) and alterations in bone geometry observed in patients with Turner syndrome (TS) are likely caused by hypergonadotropic hypogonadism and/or by haploinsufficiency of the SHOX gene. Objective: Our objective was to compare BMD, bone geometry, and strength at the radius between prepubertal girls with TS and children with isolated SHOX deficiency (SHOX-D) to test the hypothesis that the TS radial bone phenotype may be caused by SHOX-D. Design and Setting: This comparative cross-sectional study was performed between March 2008 and May 2011 in 5 large centers for pediatric endocrinology. Patients: Twenty-two girls with TS (mean age 10.3 years) and 10 children with SHOX-D (mean age 10.3 years) were assessed using peripheral quantitative computed tomography of the forearm. Main outcomes: BMD, bone geometry, and strength at 4% and 65% sites of the radius were evaluated. Results: Trabecular BMD was normal in TS (mean Z-score = -0.2 +/- 1.1, P = .5) as well as SHOX-D patients(mean Z-score = 0.5 +/- 1.5, P = .3). At the proximal radius, we observed increased total bone area (Z-scores = 0.9 +/- 1.5, P = .013, and 1.5 +/- 1.4, P = .001, for TS and SHOX-D patients, respectively) and thin cortex (Z-scores = -0.7 +/- 1.2, P = 0.013, and -2.0 +/- 1.2, P < .001, respectively) in both groups. Bone strength index was normal in TS as well as SHOX-D patients (Z-scores = 0.3 +/- 1.0, P = .2, and 0.1 +/- 1.3, P = .8, respectively). Conclusions: The similar bone geometry changes of the radius in TS and SHOX-D patients support the hypothesis that loss of 1 copy of SHOX is responsible for the radial bone phenotype associated with TS.