In addition, Zhao et al. found that children with postural tachycardia syndrome (POTS) and OHT showed higher plasma antidiuretic hormone (ADH) levels compared with children with POTS alone, and the Pearson correlation analysis showed that the plasma ADH level was positively correlated with upright SBP; thus, the increase in ADH might also be involved in the development of OHT in children (7). This evidence concerns the gene AVP and postural orthostatic tachycardia syndrome.