Inherited Disorders of Calcium, Phosphate, and Magnesium

Calcium, phosphate, and magnesium are important components of cell structure, energy metabolism, and signal transduction and are required for enzymatic activity. All of these minerals are important components of bone as well. The serum levels of these substances are tightly regulated in a narrow range with complex interactions of hormones, transporters, and receptors in many organ systems. Recent advances using animal models and humans have advanced our understanding of the regulation of these minerals. The kidneys play a critical role in fine-tuning the serum levels of these minerals. Inherited disorders of dysregulation of calcium, phosphate, and magnesium are described in detail in this chapter. Many of these disorders are present in the neonatal period, and it is vital to diagnose these disorders early so that appropriate therapy can be initiated. Although some disorders do not present in the neonatal period, it is important for the neonatologist to be aware of the later presenting conditions in order to diagnose them prior to the development of complications and to prevent late diagnosis of patients especially when there is positive family history. Understanding the inheritance of these genetic disorders can be used to provide counseling to the families.