NPHS2 Gene Mutation and Polymorphisms in Indonesian Children with Steroid-Resistant Nephrotic Syndrome

Objective: Although several NPHS2 gene mutations and polymorphisms were described and associated with clinical manifestation of steroid-resistant nephrotic syndrome (SRNS), the occurrence of these genetic abnormalities or variants appeared to be influenced by race and ethnic group. We have investigated probable mutations and variants in NPHS2 gene involved in SRNS and their association with clinical manifestations. Methods: We examined 28 children with primary SRNS who visited the pediatric nephrology division of 10 teaching hospitals in Indonesia. Molecular genetic studies of the NPHS2 gene were conducted through screenings for the exon 1, exon 2, and exon 8. The mutational analysis of NPHS2 was performed by DNA sequencing. Fisher’s Exact Test was used to determine the correlation between NPHS2 polymorphisms and clinical manifestations. Results: Seven females (25%) and 21 males (75%) participated in the study. The mean age of the subjects with 95% CI is: 7.6 (6.1 9.0) years while the mean age at onset of disease with 95% CI is: 5.4 (3.9 7.0) years. Sixteen patients (57.14%) were younger than 6 years at the onset of disease. Seventeen (60.7%) subjects had normal eGFR, while 11 (39.3%) had chronic renal insufficiency. The mean eGFR of the subjects with 95% CI is: 111.4 (87.7 135.1) ml/min/1.73 m2. The mean systolic blood pressure with 95% CI is: 117.0 (108.9 125.1) mmHg and the mean diastolic blood pressure with 95% CI is: 77.0 (70.3 83.7) mmHg. We identified 6 NPHS2 polymorphisms, i.e. g.-52G>T, c.101A>G, g.-117C>T, c.288C>T, c.954C>T, and c.1038A>G and no mutation was found. There was no correlation between NPHS2 polymorphisms and clinical manifestations (p > 0.05). Conclusion: The results demonstrate no mutation of NPHS2 gene, and the 6 NPHS2 gene polymorphisms that were identified Corresponding author.