SPLIS is caused by inactivating mutations in SGPL1 (OMIM 603729), which encodes sphingosine-1-phosphate lyase (SPL) (UNIPROT #O95470), a pyridoxal 5’-phosphate dependent enzyme that catalyzes the final step of sphingolipid metabolism [7]. The gene discussed is SGPL1; the disease is nephrotic syndrome 14.