Bone mineral content and collagen defects in osteogenesis imperfecta.
Whole-body and spine dual-energy X-ray absorptiometry was done in 63 patients with osteogenesis imperfecta aged 5 to 63 y, and the results were compared with OI types and collagen defects. Bone mineral content (BMC)-for-age, bone area (BA)-for-age, bone mineral density (BMD)-for-age, and BMC-for-BA were reduced, especially in patients with OI III/IV and/or in those with a qualitative collagen defect. BA-for-height was normal. Some patients with OI I and/or a quantitative collagen defect had BMD at or above -2 z-scores. We conclude (i) that both BMC and BMD differ significantly between OI types and collagen defects, (ii) that reduced BMC-for-age in OI patients is due mainly to reduced height ("short bones") and reduced BMC-for-BA ("light bones"), whereas BA-for-height ("bone width") is normal, (iii) that most OI patients have lower than average BMC, but in some mildly affected patients brittleness may exist with only small reductions in BMC.
Lund
A M
AM
Department of Clinical Genetics, Rigshospitalet, Copenhagen, Denmark. Lund@Biobase.dk
Mølgaard
C
C
Müller
J
J
Skovby
F
F
D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D000886:Anthropometry; D015519:Bone Density / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D003094:Collagen / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010013:Osteogenesis Imperfecta / Q000175:diagnosis* / Q000503:physiopathology*; D011379:Prognosis; D012016:Reference Values; D012680:Sensitivity and Specificity
D003094:Collagen