Bone Disease in Nephropathic Cystinosis: Beyond Renal Osteodystrophy.

Patients with chronic kidney disease (CKD) display significant mineral and bone disorders (CKD-MBD) that induce significant cardiovascular, growth and bone comorbidities. Nephropathic cystinosis is an inherited metabolic disorder caused by the lysosomal accumulation of cystine due to mutations in the gene encoding cystinosin, and leads to end-stage renal disease within the second decade. The cornerstone of management relies on cysteamine therapy to decrease lysosomal cystine accumulation in target organs.

Hyperphosphatemic tumoral calcinosis caused by FGF23 compound heterozygous mutations: what are the therapeutic options for a better control of phosphatemia?

Background: Hyperphosphatemic familial tumoral calcinosis (HFTC) is a rare autosomal recessive disease caused by mutations in genes encoding FGF23 or its regulators, and leading to functional deficiency or resistance to fibroblast growth factor 23 (FGF23). Subsequent biochemical features include hyperphosphatemia due to increased renal phosphate reabsorption, and increased or inappropriately normal 1,25-dihydroxyvitamin D (1,25-D) levels.

Case-diagnosis/treatment: A 15-year-old girl was referred for a 1.

Teenagers and young adults with nephropathic cystinosis display significant bone disease and cortical impairment.

Background: Bone impairment appears to be a novel complication of nephropathic cystinosis despite cysteamine therapy. Its exact underlying pathophysiology is nevertheless unclear. The objective of this study was to evaluate bone status among patients included in the French Crystobs study.

Bone disease in nephropathic cystinosis is related to cystinosin-induced osteoclastic dysfunction.

Background: Bone impairment is a poorly described complication of nephropathic cystinosis (NC). The objectives of this study were to evaluate in vitro effects of cystinosin (CTNS) mutations on bone resorption and of cysteamine treatment on bone cells [namely human osteoclasts (OCs) and murine osteoblasts].

Methods: Human OCs were differentiated from peripheral blood mononuclear cells (PBMCs) of patients and healthy donors (HDs).

Clinical and laboratory approaches in the diagnosis of renal tubular acidosis.

In the absence of a gastrointestinal origin, a maintained hyperchloremic metabolic acidosis must raise the diagnostic suspicion of renal tubular acidosis (RTA). Unlike adults, in whom RTA is usually secondary to acquired causes, children most often have primary forms of RTA resulting from an inherited genetic defect in the tubular proteins involved in the renal regulation of acid-base homeostasis. According to their pathophysiological basis, four types of RTA are distinguished.