Familial Renal Glucosuria and Potential Pharmacogenetic Impact on SGLT2 Inhibitors.

Background: Renal glucosuria is a rare inheritable trait caused by loss-of-function variants in the gene that encodes SGLT2 (i.e., SLC5A2). The genetics of renal glucosuria is poorly understood and even less is known on how loss-of-function variants in SLC5A2 may affect response to SGLT2 inhibitors, a new class of medication gaining popularity to treat diabetes by artificially inducing glucosuria.

Methods: We used two biobanks that link genomic with electronic health record data to study the genetics of renal glucosuria. This included 245,394 participants enrolled in the All of Us (AoU) Research Program and 11,011 enrolled in Marshfield Clinic's Personalized Research Project (PMRP). Association studies in AoU and PMRP identified 10 variants that reached an experiment-wise Bonferroni threshold in either cohort, nine were novel. PMRP was further used as a recruitment source for a prospective SGLT2 pharmacogenetic trial. During a glucose tolerance test, the trial measured urine glucose concentrations in 15 SLC5A2 variant-positive individuals and 15 matched wild types with and without an SGLT2 inhibitor.

Results: This trial demonstrated that carriers of SLC5A2 risk variants may be more sensitive to SGLT2 inhibitors compared to wild types (P=0.075). Based on population data, 2% of an ethnically diverse population carry rare variants in SLC5A2 and are at risk for renal glucosuria.

Conclusions: As a result, 2% of individuals being treated with SGLT2 inhibitors may respond differently to this new class of medication compared to the general population suggesting a larger investigation into SLC5A2 variants and SGLT2 inhibitors is needed.