NPHS2 mutations in adult patients with primary focal segmental glomerulosclerosis

Mutations in the NPHS2 gene encoding the protein podocin have recently been found in a recessive form of steroid-resistant nephrotic syndrome. Focal segmental glomerulosclerosis (FSGS) was the histologic diagnosis in many of the patients harboring these mutations. FSGS is a heterogeneous glomerular lesion with diverse origins and outcomes. Although mutational analysis in children permits the identification of an unresponsive group before initiating treatment, there is not much information on adult-onset patients with FSGS.

We performed NPHS2 gene mutational analysis in 39 adult Brazilian patients with primary FSGS, and evaluated the clinical course of the disease and response to treatment; in addition, we performed urinary screening in 44 relatives of these patients.

In this group, only 1 patient (with familial FSGS) had a mutation in the NPHS2 gene with double heterozygosity. The absence of mutations in all other patients evaluated suggests its rarity in sporadic cases of adult-onset (steroid sensitive or resistant) FSGS in our population.

Our results suggest that the analysis of the NPHS2 gene mutation is not indicated as a routine diagnostic procedure in our population for adult-onset patients with FSGS.