The NIPA family is currently comprised of 4 members: NIPA1-4. These members have a molecular similarity of 40%. They are integral membrane proteins which function as Mg²⁺ transporters.

While NIPA2 is highly selective for Mg²⁺ transportation, other members of the family transport other cations as well. NIPA2 has 9 transmembrane protein domains. It is also found in the early endosome and transfers extracellular Mg²⁺ into the cytoplasm. NIPA2 is highly conserved among vertebrates; human and mouse NIPA2 have a 96% amino acid identity. NIPA2 is expressed in the heart, CNS and pancreas. Its expression is upregulated in MDCT cells cultured in low-magnesium levels compared to normal magnesium.

Several imprinted genes have been identified as candidates for prader-willi syndrome in the 15q11-q13 region however the involvement of NIPA2, which resides in this region, remains unclear. Currently there is no evidence that the gene is directly involved in the many complexities of the syndrome- Mouse models of prader-willi-like pathologies include severe failure to thrive and early postnatal lethality have not implicated NIPA2¹.

NIPA2 has also been recently implicated in the pathogenesis of childhood absence epilepsy (CAE). NIPA2 mutations have been found in some CAE patients. These mutations comprise of 2 missense mutations and a small insertion mutation. All mutations are heterozygous and are inherited from the paternal side. These mutations affect the highly conserved amino-acid structure of the transporter².