Introduction:
Nephrotic syndrome is the most common glomerular disease in children but it rarely presents in the first year of life. It is defined as congenital nephrotic syndrome (CNS) if the disease onset is in the first 3 months of life or infantile nephrotic syndrome if it occurs between 3 to 12 months of life. This study aimed to analyze infants' clinical spectrum, genetic profile, renal biopsy, and outcome at the end of follow-up period.
Methods:
In this study, 35 children who were diagnosed with infantile nephrotic syndrome (INS) between August 2020 and August 2024 in the Division of Pediatric Nephrology, SVPPGIP, and SCB Medical College, Odisha were included. These children were treated initially with oral prednisolone. Whole exome sequencing could be performed in 8 patients and the pathogenicity of variants could be interpreted. These children were subsequently on regular follow-up for up to 48 months and those showing frequent relapses while receiving corticosteroids or found to be steroid-resistant were treated with steroid-sparing agents.
Results:
Of the 35 children diagnosed with INS,17 children (48%) were found to be male, 9 children (25%) showed initial response to steroids while the remaining showed primary steroid resistance.
8 samples sent for whole genome sequencing had findings, the mutations found were NPHS1 (3 children), PLCE1 mutation (1 child), OSGEP mutation (Galloway Mowat syndrome, 1 child), DRC1 mutation (1 child), COL4A5 mutation (1 child) and ALPK1 mutation (1 child). About 75% of children with infantile nephrotic syndrome who underwent whole exome sequencing were found to have an underlying genetic abnormality consistent with the same.
Renal biopsy had been conducted for a total of 16 patients. FSGS (50%) was the most common renal histopathology finding followed by MCD in 6 patients (37%) and 2 patients had IgMN.
During follow up it was found that a patient with NPHS1 mutation (sibling death due to a similar reason) and one with PLCE1 mutation (maternal history of systemic sclerosis and congenital heart disease and CMV positive) succumbed to the disease process. While on treatment 15 children (42%) showed complete remission with CNI, 13 children (37%) had partial remission with CNI and only 2 children showed complete remission while on corticosteroid. One patient with NPHS1 mutation has been in remission and CNI for the last seven years. The persistent proteinuria in the partial remission group was difficult to treat and resulted in a greater number of relapses.
Conclusions:
NPHS1 mutation was the most common cause of infantile nephrotic syndrome in our cohort. Most cases of INS children responded to CNI (complete or partial), irrespective of underlying genetic mutation or renal histopathology however, frequent relapses were seen in groups with partial remission with CNI which required prolonged hospital admission and were associated with complications.
This abstract was also submitted for consideration in IPNA Congress 2025. Permission was granted for re-submission.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.