Bone Abstracts

Background: Genetic disorders of mineral metabolism causing nephrolithiasis and bone abnormalities are uncommon and have a varied clinical spectrum. Hypophosphataemic rickets with hypercalciuria (HHRH) is a rare autosomal-recessive condition, typically presenting with severe rickets and hypophosphataemia. Milder forms can present with hypercalciuria and nephrolithiasis without bone disease. The underlying pathophysiology is due to mutations in the SLC34A3 gene, which encodes t...

Background: Children with special needs may be greater risk of vitamin D deficiency due to decreased mobility and outdoor play, concomitant medications that increase catabolism of vitamin D, reduced nutritional intake and low body weight. Gastrostomy-fed children receiving a nutritionally complete formula may still be at risk of vitamin D deficiency due to the above factors.Objective: The objective of this study is to assess the vitamin D status of speci...

Background: Fibrodysplasia ossificans progressiva (FOP) is a rare condition characterised by congenital malformation of the great toes and progressive heterotopic endochondral ossification. The disease progresses with episodic flare-ups, resulting in disabling cumulative immobility. The discovery of the ACVR1 gene as the cause of FOP has allowed identification of therapeutic targets. Palovarotene, a retinoic acid receptor gamma agonist, is in phase 2 clinical trials.<...

Delta-like 1/fetal antigen-1 (DLK1/FA1) is a negative regulator of bone mass in vivo as it inhibits osteoblast (OB) and stimulates osteoclast differentiation. However, the molecular mechanisms underlying these effects are not known. Thus, we studied the effect of DLK1/FA1 on different signaling pathways known to regulate OB differentiation. We identified DLK1/FA1 as an inhibitor of BMP2-induced OB differentiation. Stable overexpression of DLK1/FA1 in C2C12 cells or th...

Background: Infantile hypercalcemia occurs in ~15% of patients with Williams Syndrome (WS) and is typically mild. Severe hypercalcemia has been reported in infants/toddlers with WS, requiring treatment with intravenous (IV) saline hydration, furosemide, calcitonin, calcium and vitamin D restriction, and in some cases IV bisphosphonates.Presenting problem: Three cases of infants with WS age 9–13 months presented with severe hypercalcemia, failure to ...

Duchenne muscular dystrophy (DMD) causes progressive muscle weakness and loss of ambulation. While glucocorticoid (GC) therapy improves motor function, many boys sustain fractures due to osteoporosis. Recently, i.v. bisphosphonate (i.v.BP) therapy has shown promise in the treatment of DMD-related osteoporosis. At the same time, bone histomorphometry revealed lowered bone volume and significant reductions in bone formation pre-i.v.BP treatment, and a further drop after 2 years&...

Introduction: Acromegaly is a rare disease caused by excess growth hormone (GH) production by an adenoma of the anterior pituitary gland. The skeletal complications of GH and IGF-1 excess include increased bone turnover, increased cortical bone mass and deteriorated microarchitecture of trabecular bone, associated with a high risk of vertebral fractures in the presence of a relatively normal Bone Mineral Density (BMD). There are no data on bone material properties in patients ...

Skeletogenesis is an intricate process controlled by numerous transcriptional factors, hormones and signalling pathways. Recently, microRNAs emerged as important players in skeletogenesis but, only few were identified and most of their targets remain unknown. Previous works showed that miR-199a-2/214 cluster is essential for skeletal development and that miR-214 inhibits bone formation in mammals. However, data regarding its skeletal role in other vertebrates is scarce and its...

Background: Severe vitamin D deficiency (VDD), is a common disorder, which has complications including rickets, hypocalcaemia, hypotonia, delayed development and cardiomyopathy. Although nutritional rickets associated craniosynostosis has been reported, there is little awareness of this or knowledge about its clinical course or severity. We present five cases of late onset craniosynostosis in association with nutritional rickets.Clinical presentation: Th...

Background: Mutations in SATB2 have been described in association with a unique phenotype known as SATB2-associated syndrome (SAS). This condition is characterised by severe intellectual disability affecting speech development, behaviour, facial features and dental anomalies. Skeletal features and osteoporosis have been reported in older individuals (aged 15–36), in association with point mutations. We report a 24-year-old man with a SATB2 misse...