SLC6A6 and obesity due to melanocortin 4 receptor deficiency: In preliminary studies, we also found that maternal plasma taurine concentration at term was significantly higher in obese than in ideal weight women (38±2.6 μm; n=13 vs 29.6±2.3 μm; n=11, respectively51), raising the possibility that reduced placental TauT activity in obesity may be an adaptive response to elevated maternal plasma taurine concentration.