High throughput sequencing in sporadic forms of steroid-resistant nephrotic syndrome in children frequently identifies heterogeneous genetic alterations that predict resistance to immunosuppressive treatments

Mazzinghi, B.;GIGLIO, SABRINA RITA;PROVENZANO, ALDESIA;BECHERUCCI, FRANCESCA;Sansavini, G.;Ravaglia, F.;ROMAGNANI, PAOLA

2014-01-01

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Abstract

In children, sporadic nephrotic syndrome can be related to a genetic cause, but to what extent genetic alterations associate with resistance to immunosuppression is unknown. In this study, we designed a custom array for next-generation sequencing analysis of 19 target genes, reported as possible causes of nephrotic syndrome, in a cohort of 31 children affected by sporadic steroid-resistant nephrotic syndrome and 38 patients who exhibited a similar but steroid-sensitive clinical phenotype. Patients who exhibited extrarenal symptoms, had a familial history of the disease or consanguinity, or had a congenital onset were excluded. We identified a genetic cause in 32.3% of the children with steroid-resistant disease but zero of 38 children with steroid-sensitive disease. Genetic alterations also associated with lack of response to immunosuppressive agents in children with steroid-resistant disease (0% of patients with alterations versus 57.9% of patients without alterations responded to immunosuppressive agents), whereas clinical features, age at onset, and pathologic findings were similar in steroid-resistant patients with and without alterations.