Bone Abstracts

Objectives: CKD in children is associated with suppressed body growth. Physical activity has been previously shown to increase expression of IGF1 signaling in muscles of rats with CKD, but the effects of this intervention on bone tissue have not been investigated yet. The purpose of this study was to examine the effects of aerobic exercise on CKD related bone disease.Methods: Twenty-day old/50 g male rats underwent a two step subtotal nephrectomy (Nx) or...

Introduction: Children with chronic kidney disease (CKD) who suffer from growth retardation have usually normal circulating GH but low IGF1, suggesting GH resistance. We have previously shown in growth retarded CKD rats an increase in suppressor of cytokine signaling 2 (SOCS2) levels, a key negative regulator of GH signaling. SOCS2 spontaneously mutated (HG) mice show an exaggerated body growth and increased bone mass. We investigated growth and GH receptor (GHR) signaling in ...

Background: Pseudohypoparathyroidism type 1A (PHP1A) is a rare genetic disorder caused by mutations in the gene GNAS. It is characterized by multi-hormone resistance, obesity, cognitive impairment and the Albright hereditary osteodystrophy phenotype. A recent study found a 4.4-fold increase risk of sleep apnea in children with PHP1A compared with similarly obese children.Objective: To describe a case of morbid obesity and respiratory failure in ...

Background: Osteolytic lesions can be the presenting manifestation of various medical conditions, including bone tumors (benign and malignant) and infectious and endocrine diseases.Presenting problem: A 19-year-old Bedouin male from a consanguineous family was referred to our medical center for orthopedic consultation due to a pathological fracture and a cystic lesion in his right ulna. A skeletal survey revealed another cystic lesion in the left tibia. ...

Objective: Burosumab, a recombinant human monoclonal antibody that inhibits FGF23, was approved by the FDA in April, 2018 for the treatment of X-linked hypophosphatemia (XLH) in children and adults. XLH pediatric patients are typically affected with lower extremity deformities, short stature, bone pain, and limited physical activity. Burosumab is superior to conventional therapy in normalizing blood phosphate levels, thereby healing rickets, decreasing leg bowing, and reducing...

Background: Loss of function mutations of CYP24A1, encoding vitamin D-24-hydroxylase, have been recently identified in idiopathic infantile hypercalcemia (IIH), a rare entity which may lead to severe complications.Objective: We describe an infant with IHH due to a novel CYP24A1 mutation and a unique neurological presentation.Case presentation: The patient was born at term after normal pregnancy to healthy non-cons...

Purpose: The aim of this research was to develop an in vivo platform for conveniently examining the potential of various factors to augment chondral bone regeneration. For this purpose, we have established a de novo partial tail amputation model in adult zebrafish, which includes the resection of cartilage-template based bones from the endoskeletal caudal complex. Endoskeletal amputations were rarely studied, as opposed to those of the distal caudal fin rays, a well-e...

Background: X-linked hypophosphatemic rickets (XLH) is characterized by hypophosphatemia, bone deformities, and growth retardation. Conventional treatment of XLH with oral phosphate supplementation and high doses of vitamin D fails to normalize linear growth and adult stature remains disproportionately short. Few studies report on the use of recombinant human growth hormone (rhGH) therapy in pre-pubertal children with XLH.Presenting problem: Two brothers...

Background: Calcinosis cutis, the deposition of insoluble calcium salts in the cutaneous and subcutaneous tissue, is rare during infancy. Calcifications are most frequently reported after subcutaneous fat necrosis, hypothermia in neonates or following extravasation of calcium gluconate.Presenting problem: The patient was born at term by caesarean section because of fetal distress; the birth weight was 2426 g. At age 4 weeks, he was admitted to the hospit...

Background: Vitamin D-dependent rickets type 1 (VDDR-1) is a rare autosomal recessive disorder caused by mutations in CYP27B1. This gene encodes the 1α-hydroxylase enzyme which converts 25-hydroxy vitamin D to the active form 1,25-dihydroxyvitamin D.Objective: To describe a case of VDDR-1due to a novel CYP27B1 mutation.Presenting problem: A 27-month-old female was admitted to the Pediatric Intensive Care Unit...