Bone Abstracts

Recessive osteogenesis imperfecta (OI) is caused by mutations in genes encoding proteins involved in post-translational interactions with type I collagen. A founder mutation in a new gene responsible for recessive OI has recently been reported in Bedouins from Israel and Saudi Arabia, who have a homozygous deletion of TMEM38B exon 4 and surrounding intronic sequence. TMEM38B encodes TRIC-B, an integral ER membrane monovalent cation channel involved in Ca...

Classical osteogenesis imperfecta (OI) is caused by mutations in the two genes encoding type I collagen. OI is associated with low bone mass and abnormally high bone matrix mineralization. The Brtl/+ OI mouse is a knock-in model caused by a glycine substitution in one COL1A1 allele. Brtl/+ pups display 30% perinatal lethality; survivors have small size and brittle bone. Unexpectedly, homozygous Brtl/Brtl pups, producing only mutant collagen, have normal survival rates...

The quantitative ultrasound (QUS) of the proximal phalanges has been used for the indirect evaluation of bone status. Furthermore, the relative simplicity and non-exposure to radiation, presents advantages for the use of QUS compared to other methods in children and adolescents. The aim of this study was to determine the influence of age and pubertal development on Amplitude Dependent Speed Sound (AD-SoS) assessed by QUS of proximal phalanges in girls and boys aged 10–15 ...

Background: Congenital multiple hormone deficiency (CMHD) is a rare condition caused by mutations in transcription factors involved in pituitary ontogenesis1. Incidence of mutations in POU1F1 gene in results between 3.8 and 7.7%2. POU1F1 gene mutations lead to somatolactotroph and thryotroph deficiencies. Brain MRI can be normal or shows pituitary hypoplasia without extrapituitary anomalies.Presenting problem: We describe the growth...

Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenic cause of renal failure. Data from adult ADPKD population show increased fibroblast growth factor 23 (FGF23) levels while circulating Klotho levels decrease, with a low TmP/GFR even in patients with normal renal function. Moreover, in ADPKD animal models, cyst lining renal cells were demonstrated to produce FGF23, although the animals displayed FGF23 resistance. No data are available in a paediatr...

Background and Objectives: The relations among cortical volumetric bone mineral density (CortBMD) and comprehensive measures of mineral metabolism have not been addressed in chronic kidney disease (CKD). The aim was to identify determinants of CortBMD in childhood CKD. A secondary objective was to assess if CortBMD was associated with subsequent fracture.Design/participants: This prospective cohort study in children, adolescents and young adults (ages 5&...

Osteogenesis imperfecta (OI) is a heritable bone dysplasia with collagen-related defects. Dominantly inherited OI is caused by structural defects in type I collagen or IFITM5, while recessive forms are caused by deficiency of proteins that interact with collagen for modification, folding or cross-linking. We have identified the first X-linked form of OI, caused by a defect in regulated intramembrane proteolysis (RIP). One type of RIP involves sequential cleavage of regulatory ...

Objectives: We evaluated the efficacy and safety of intravenous zoledronic acid (IV ZA) in children with glucocorticoid-induced osteoporosis (GIOP) through a randomized, placebo (PBO)-controlled trial.Methods: In this multi-national Phase 3 trial (NCT00799266), children 5–17 years of age with GIOP and low-trauma vertebral fractures (VF) were randomized 1:1 to IV ZA 0.05 mg/kg or IV PBO every six months for one year. Changes in lumbar spine areal bon...

Objectives: To describe the incidence of vertebral fractures in steroid-treated children.Methods: Fractures were assessed prospectively each year for 3 years according to the Genant semi-quantitative method. Proportions of children with incident fractures were determined annually over the study period. To examine associations with baseline clinical factors, the 3-year total number of incident fractures was analyzed using multivariable Poisson regression....

Introduction: Resistance to thyroid hormone (RTH) is a rare disease, characterized by elevated thyroid hormone and not suppressed TSH concentrations. In 85% of cases it is related to TRβ gene mutations.Objectives: To evaluate biochemical and densitometric features of 14 patients with RTH (RTHG: 7 females (4 children) and seven males (2 children)) in comparison to 24 control subjects (CG, 14 females (8 children) and 10 males (4 children)).<p clas...