SLC20A2

SLC20A2 is a gene that encodes a protein known as the sodium-dependent phosphate transporter 2 (PiT-2). This protein is a member of the solute carrier family 20 and plays a crucial role in phosphate homeostasis in the human body.

Function

The SLC20A2 gene product, PiT-2, is primarily involved in the transport of inorganic phosphate across cell membranes. This process is essential for various physiological functions, including bone mineralization, energy metabolism, and nucleotide synthesis. PiT-2 operates as a symporter, utilizing the sodium gradient across the cell membrane to facilitate phosphate uptake.

Expression

SLC20A2 is ubiquitously expressed in many tissues, with particularly high expression levels in the brain, kidney, and liver. The expression of SLC20A2 is regulated by dietary phosphate levels, hormonal signals, and other factors that influence phosphate metabolism.

Clinical Significance

Mutations in the SLC20A2 gene have been associated with a rare genetic disorder known as familial idiopathic basal ganglia calcification (FIBGC), also referred to as Fahr's disease. This condition is characterized by abnormal calcium deposits in the basal ganglia and other brain regions, leading to neurological symptoms such as movement disorders, cognitive impairment, and psychiatric disturbances.

Pathophysiology

The exact mechanism by which SLC20A2 mutations lead to brain calcification is not fully understood. However, it is hypothesized that impaired phosphate transport disrupts phosphate homeostasis, leading to abnormal calcium-phosphate deposition in the brain. This pathological calcification is thought to interfere with normal neuronal function, resulting in the clinical manifestations of the disease.

Research Directions

Ongoing research is focused on understanding the precise role of SLC20A2 in phosphate metabolism and its contribution to neurological disorders. Studies are also exploring potential therapeutic strategies to modulate phosphate transport and prevent or reverse brain calcification in affected individuals.

Also see

• Phosphate homeostasis
• Familial idiopathic basal ganglia calcification
• Solute carrier family
• Sodium-phosphate transporters