TY - JOUR
T1 - DXA measurements in rett syndrome reveal small bones with low bone mass
AU - Roende, Gitte
AU - Ravn, Kirstine
AU - Fuglsang, Kathrine
AU - Andersen, Henrik
AU - Bieber Nielsen, Jytte
AU - Brøndum-Nielsen, Karen
AU - Jensen, Jens-Erik Beck
N1 - Copyright © 2011 American Society for Bone and Mineral Research.
PY - 2011/9/1
Y1 - 2011/9/1
N2 - Low bone mass is reported in growth-retarded patients harboring mutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene causing Rett syndrome (RTT). We present the first study addressing both bone mineral density (BMD) and bone size in RTT. Our object was to determine whether patients with RTT do have low BMD when correcting for smaller bones by examination with dual-energy X-ray absorptiometry (DXA). We compared areal BMD (aBMD spine and aBMD total hip) and volumetric bone mineral apparent density (vBMAD spine and vBMAD neck) in 61 patients and 122 matched healthy controls. Further, spine and hip aBMD and vBMAD of patients were associated with clinical risk factors of low BMD, low-energy fractures, MECP2 mutation groups, and X chromosome inactivation (XCI). Patients with RTT had reduced bone size on the order of 10% and showed lower values of spine and hip aBMD and vBMAD (p<.001) adjusted for age, pubertal status, and body mass index (BMI). aBMD spine, vBMAD spine, and aBMD total hip were associated with low-energy fractures (p<.05). Walking was significantly associated to aBMD total hip and vBMAD neck adjusted for age and body mass index (BMI). Further, vBMAD neck was significantly associated to a diagnosis of epilepsy, antiepileptic treatment, and MECP2 mutation group, but none of the associations with vBMAD neck remained clinically significant in a multiple adjusted model including age and BMI. Neither aBMD spine, vBMAD spine, nor aBMD total hip were significantly associated with epilepsy, antiepileptic treatment, MECP2 mutation group, XCI, or vitamin D status. Low bone mass and small bones are evident in RTT, indicating an apparent low-bone-formation phenotype.
AB - Low bone mass is reported in growth-retarded patients harboring mutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene causing Rett syndrome (RTT). We present the first study addressing both bone mineral density (BMD) and bone size in RTT. Our object was to determine whether patients with RTT do have low BMD when correcting for smaller bones by examination with dual-energy X-ray absorptiometry (DXA). We compared areal BMD (aBMD spine and aBMD total hip) and volumetric bone mineral apparent density (vBMAD spine and vBMAD neck) in 61 patients and 122 matched healthy controls. Further, spine and hip aBMD and vBMAD of patients were associated with clinical risk factors of low BMD, low-energy fractures, MECP2 mutation groups, and X chromosome inactivation (XCI). Patients with RTT had reduced bone size on the order of 10% and showed lower values of spine and hip aBMD and vBMAD (p<.001) adjusted for age, pubertal status, and body mass index (BMI). aBMD spine, vBMAD spine, and aBMD total hip were associated with low-energy fractures (p<.05). Walking was significantly associated to aBMD total hip and vBMAD neck adjusted for age and body mass index (BMI). Further, vBMAD neck was significantly associated to a diagnosis of epilepsy, antiepileptic treatment, and MECP2 mutation group, but none of the associations with vBMAD neck remained clinically significant in a multiple adjusted model including age and BMI. Neither aBMD spine, vBMAD spine, nor aBMD total hip were significantly associated with epilepsy, antiepileptic treatment, MECP2 mutation group, XCI, or vitamin D status. Low bone mass and small bones are evident in RTT, indicating an apparent low-bone-formation phenotype.
U2 - 10.1002/jbmr.423
DO - 10.1002/jbmr.423
M3 - Journal article
C2 - 21590733
SN - 0884-0431
VL - 26
SP - 2280
EP - 2286
JO - Journal of Bone and Mineral Research
JF - Journal of Bone and Mineral Research
IS - 9
ER -