title: Bone geometry and volumetric bone density at the radius in patients with isolated SHOX deficiency.
abstract: The short stature homeobox-containing gene (SHOX) plays an important role in bone development and growth. We aimed to assess bone geometry and volumetric bone mineral density at the radius in patients with isolated SHOX deficiency and to relate these bone parameters to the severity of disproportion between the upper and the lower body segment. 17 patients with isolated SHOX deficiency (median age 12.3 yrs, range 6.7-37.2, 12 children and 5 adults) were examined by peripheral quantitative CT (pQCT) at the non-dominant forearm. Results were expressed as Z-scores using published reference data. Linear regression analyses were performed to describe associations between pQCT parameters and the severity of disproportion expressed as sitting height to standing subischial leg height ratio. Trabecular volumetric bone mineral density (vBMD) at the distal radius was normal, whereas cortical vBMD was decreased (mean Z-scores 0.34±1.5, n.s., and -2.2±2.2, p<0.001, respectively). Total bone cross-sectional area was enlarged at the diaphysis (2.1±1.2, p<0.001), while cortical bone cross-sectional area was normal (-0.51±1.4, n.s.). Consequently, cortical thickness was decreased (-1.2±1.3, p<0.01). The polar strength-strain index as a surrogate of long bone strength was normal (0.40±1.4, n.s.). We found no associations between pQCT parameters and the severity of disproportion.
  
  
  CONCLUSIONS
  Patients with isolated SHOX deficiency are characterized by decreased cortical vBMD and cortical thickness and enlarged diaphysis. As similar changes have been described in girls with Turner syndrome, these findings suggest that haploinsufficiency of SHOX could cause characteristic skeletal anomalies at the radius.
authors: Department of Paediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic. ondrej.soucek@lfmotol.cuni.cz
authors: O
authors: O
authors: Soucek
authors: J
authors: J
authors: Lebl
authors: J
authors: J
authors: Zapletalova
authors: D
authors: D
authors: Novotna
authors: I
authors: I
authors: Plasilova
authors: S
authors: S
authors: Kolouskova
authors: D
authors: D
authors: Zemkova
authors: M
authors: M
authors: Rocek
authors: Z
authors: Z
authors: Hlavka
authors: K
authors: K
authors: Hirschfeldova
authors: Z
authors: Z
authors: Sumnik
mesh_terms: D000293:Adolescent; D041923:Adolescent Development; D000328:Adult; D000465:Algorithms; D049628:Body Size; D015519:Bone Density; D001846:Bone Development; D002648:Child; D002657:Child Development; D018483:Diaphyses / Q000000981:diagnostic imaging; D005260:Female; D006130:Growth Disorders / Q000000981:diagnostic imaging* / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D057895:Haploinsufficiency; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008297:Male; D011884:Radius / Q000000981:diagnostic imaging* / Q000378:metabolism; D012720:Severity of Illness Index; D000074122:Short Stature Homeobox Protein; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D018398:Homeodomain Proteins; C106071:SHOX protein, human; D000074122:Short Stature Homeobox Protein