In patients with skeletal symptoms and bone mineral disorders (bone deformations, bone pain, history of fragility fractures), it is necessary to assess and monitor parameters of calcium-phosphate metabolism (Ca, PO4, ALPL, PTH and Ca/creatinine ratio in urine), and if available—to examine bone mineral density using DXA (2⊕⊕);. This evidence concerns the gene PTH and abnormal mineralization disorder.