Genetic variants in SLC9A9 gene coding for sodium/hydrogen exchanger 9 are not associated with diabetic kidney disease

Abstract

Background. Several independent studies found a linkage between diabetic kidney disease and chromosome 3q22. Following studies were not able to found a genetic polymorphism in the chromosome 3q22 region which was associated with diabetic kidney disease and which could explain the observed linkage. The SCL9A9 gene coding for the sodium/hydrogen exchanger 9 is located in the critical region on chromosome 3q22. Genetic variants of the SCL9A9 gene might be involved in the abnormal kinetics of erythrocyte sodium-lithium countertransport observed in patients with diabetic kidney disease. The aim of the study was to check the association between genetic polymorphisms of the SCL9A9 gene and diabetic kidney disease.

Material and methods. We collected 61 patients with diabetic kidney disease and 63 patients with normoalbuminuria after at least 15 years of known diabetes duration. Peripheral blood was drawn and DNA was extracted from leukocytes. Fragments of the SCL9A9 gene were amplified by PCR and digested by specific restriction enzymes. Altogether 3 polymorphisms were genotyped: rs17594058 in intron 1, rs7641634 in intron 2 and rs6763202 in exon 8. The genotype frequency was compared between patients with and without diabetic kidney disease.

Results. There was no difference in the genotype frequency for analyzed polymorphisms in the SCL9A9 gene between patients with and without diabetic kidney disease.

Conclusions. The genetic variants of the SCL9A9 gene localized in the critical region on chromosome 3q22 are not associated with diabetic kidney disease.