SLC2A2
The SLC2A2 gene encodes GLUT2, a carrier protein that enables facilitated glucose movement across cell membranes. GLUT2 is the main transporter for the transfer of glucose between the blood and liver, and can also transport glucosamine and fructose. GLUT2 is also required for glucose sensing by cells of the central nervous system and the absence of central GLUT2-dependent glucose sensing (such as with genetic variations) impairs the normal sensitivity of the melanocortin pathway to leptin and is associated with impaired control of feeding and thermoregulation. Glucose sensing means that the rate of glucose entry is proportional to blood glucose levels. GLUT2 functions as a "glucose detection mechanism" in direct response to changes in glucose concentrations. For example, the taste bud cells sense the presence of sugar in food and initiate insulin secretion.
The A-genotype is associated with high habitual consumption of sugars (approximate 1.5 times compared to the normal genotype), suggesting that the underlying mechanism regulates food intake, impaired fasting glucose or insulin resistance, increased risk for Type II diabetes, increased risk for elevated cholesterol levels, and increased caries prevalence.
