Hypophosphatemic Rickets in Norway
HypophosphatemiaFamilial2 moreThe purpose of the study is to do a follow-up survey of all individuals with hereditary hypophosphatemia in Norway, focusing on manifestations in childhood and adolescence. The investigators also want to study phenotype-genotype associations, and look for new genes, in all forms of hereditary hypo and hyperphosphatemia.
Natural History of GACI With or Without ARHR2 or PXE
Generalized Arterial Calcification in InfancyAutosomal Recessive Hypophosphatemic Rickets1 moreGeneralized arterial calcification of infancy (GACI) is an ultra-rare disorder with an estimated birth prevalence of around 1 in 400,000.1 GACI is generally fatal before birth or within the first six months after birth. The cause of death is frequently myocardial infarction or stroke. GACI is strongly associated with inactivating mutations in ectonucleotide pyrophosphate/ phosphodiesterase 1 (ENPP1). Many patients with GACI, including some without an ENPP1 mutation also present with mutations in adenosine triphosphate binding cassette transporter protein subfamily C member 6 (ABCC6). Autosomal recessive hypophosphatemic rickets type 2 (ARHR2) and pseudoxanthoma elasticum (PXE) are believed to be closely related to GACI. ARHR2 is caused by mutations in the ENPP1 gene and PXE is caused by mutations in the ABCC6 gene, with both being observed among patients with GACI. The natural history of GACI and in particular its long term morbidity and mortality are poorly understood. The primary objective of this study is to characterize overall survival among patients with GACI, over time from birth.