Human SMIT is a high-affinity myo-inositol transporter, and is expressed in brain, heart, kidney, and lung. Inhibition of myo-inositol uptake, through down-regulation of SMIT, may be a common mechanism of action of mood stabilizers, including lithium, carbamazepine, and valproate []. SMIT is encoded by the SLC5A3 gene, which is a candidate gene for pathogenesis of nervous system dysfunction in Down syndrome (DS) []. The SNP, 21q22 near SLC5A3-MRPS6-KCNE2, has been associated with coronary heart disease, cardiovascular disease, and myocardial infarction []. SMIT may also be involved in the pathogenesis of congenital cataract []. SMIT also plays roles in osteogenesis, bone formation, and bone mineral density determination. SMIT belongs to the solute carrier 5 (SLC5) transporter family [].
