Rare disorders of calcium and phosphate are characterized by abnormalities in their regulatory hormones (namely vitamin D, PTH and FGF23), including elevated levels of 1,25(OH)₂ vitamin D, whether primary or secondary. The objective of this presentation is to provide an update on these rare diseases characterized by elevated 1,25(OH)₂ vitamin D levels, particularly mutations in 24-hydroxylase (CYP24A1 gene) and sodium/phosphate co-transporters (SLC34A1 and SLC34A3 genes). Well known by nephrologists and pediatric nephrologists because of the high incidence of kidney stones and nephrocalcinosis, these diseases raise multiple questions: diagnosis delay (observed in almost all rare diseases despite national and European healthcare networks), role of heterozygosity in the phenotypic spectrum, management (currently symptomatic with the hope of new targeted therapies), potential impact on neonatal genomic screening in a near future, etc.