Background: The angiotensin converting enzyme (ACE) gene carries insertion (I) and deletion (D) polymorphism within its intron 16. The presence of D-allele in the ACE gene has been reported as a probable genetic risk factor for idiopathic nephrotic syndrome (INS), especially the subtype of focal segmental glomerulosclerosis (FSGS). The D-allele may be related to poor responsiveness to steroid therapy. To clarify the relationship between the D-allele and INS, we studied the prevalence of the D-allele in the Javanese-Indonesian patients. Additionally, we also analyzed relationship between each genotype and steroid sensitivity among the MCNS patients.
Methods: Eighty-five Javanese-Indonesian patients under 15 years of age with INS were enrolled in this study: 16 patients with FSGS and 69 patients with minimal change nephrotic syndrome (MCNS). As controls, 68 healthy adult Javanese-Indonesians with no history of kidney disease volunteered to participate in this study. Genotypes based on the polymorphisms (I/D) were determined by using a PCR method. As for the steroid responsiveness, the information of 14 out of 16 FSGS patient (87.5%) and 69 out of 69 MCNS patients (100%) was available.
Results: The genotype frequencies in the FSGS patients were II 37% (6/16), ID 44% (7/16) and DD 19% (3/16), and the D-allele frequency was 41% (13/32). The genotype frequencies in the MCNS patients were II 56% (39/69), ID 38% (26/69) and DD 6% (4/69), and the D-allele frequency was 25% (34/138). The genotype frequencies in the controls were II 60% (41/68), ID 31% (21/68), and DD 9% (6/68), and the D-allele frequency was 26% (33/136). None of the FSGS patients were sensitive to steroid, while almost all MCNS patients (66/69) were sensitive to steroid. The genotype frequencies among steroid-sensitive MCNS patients were consistent with those of the controls, suggesting that there was no relationship between each genotype and steroid sensitivity.
Conclusions: In the Javanese-Indonesian population, none of the comparisons showed any significant differences in the genotypic distribution and allelic frequencies among the three groups, FSGS, MCNS and controls, although D-allele tended to exist more frequently in FSGS patients than in the MCNS patients and controls. In addition, the D-allele frequency was not related to steroid sensitivity in the MCNS patients.