Transient Congenital Nephrotic Syndrome in Neonates: Two Case Reports and Review of Recent Literature

We report two cases of non-genetic transient congenital nephrotic syndrome (CNS) in neonates, both presenting with hydrops fetalis associated with nephrotic range proteinuria and significant hypoalbuminemia. Investigations did not reveal any underlying genetic cause or congenital infection to explain the nephrotic syndrome. Both cases received supportive therapy and showed spontaneous recovery with resolution of proteinuria and normalization of serum albumin in a few weeks. These cases underscore the diagnostic and prognostic uncertainties in CNS without identifiable genetic or infectious causes and highlight a possible transient or stress-induced phenotype not previously well-characterized in the literature. Furthermore, this raises the question of whether we need to redefine the definition of CNS by adding a minimum duration after which an infant will be labeled as having CNS.