This study identified a SLC17A9 missense variant c.932G>A in a DSAP family by exome sequencing. The c.25C>T variant in additional family supported an important role of SLC17A9 in DSAP.

SLC17A9 encoded a vesicular nucleotide transporter (VNUT), which contributed to ATP vesicle formation and ATP release regulation. The two identified variants located in major facilitator superfamily domain, general substrate transporter. This domain functioned as lycerol-3-phosphate transporter and it consists of 12 transmembrane helix.

The probable mechanism of mutated SLC17A9 in DSAP may be associated with delayed ATP efflux and calcium release into periplasm. (By Dr. Hongzhou Cui, http://jmg.bmj.com/content/early/2014/09/01/jmedgenet-2014-102486 )