Non-replication of an association between the Odd-skipped related 1 c.654G>A (rs12329305) polymorphism and kidney volume in newborns

Introduction: Odd-skipped related 1 (Osr1) protein is a marker of intermediate mesoderm from which all definitive kidney progenitor cells develop. The loss-of-function OSR1 c.654G>A (rs12329305) polymorphism has been associated with a reduced kidney volume at birth and congenital renal anomalies.

The aim of this study was to re-investigate whether the OSR1 c.654A allele is associated with a smaller kidney volume (a surrogate of the congenital nephron number) in newborns, either alone or in combination with RET c.1296G>A(RET x OSR1 interaction).

Materials and methods: A total of 178 healthy, full-term Polish newborns were included in this study. Kidney size was measured by ultrasound on the third day of life and normalised for body surface area (TKV/BSA). The OSR1 polymorphism was identified by mini-sequencing. The reduced model without interaction and the full model including interaction terms were compared using the F test.

Results: TKV/BSA did not differ across the genotype groups, t(176) = −0.45, p = 0.653 (106 ±24 and 108 ±25 mL/m2 for GG and GA, respectively). Similarly, there was no effect of the c.654G>A geno-type on TKV/BSA after controlling for the effect of covariates, F(1,175) = 0.28, p = 0.598. There was no association of the RET x OSR1 interaction on the TKV/BSA.

Conclusion: We did not find an association between the OSR1 c.1296G> A polymorphism, alone and in combination with RET c.645G> A and kidney size in a group of healthy full-term newborns.