[Focal segmental glomerulosclerosis related to BK virus in a child with nephrotic syndrome. A case report].

Background: focal segmental glomerulosclerosis (FSGS) is observed in about 10 % of children with idiopathic nephrotic syndrome; this disorder is usually resistant to corticoid therapy. In the last few years, five histological types of FSGS have been recognized; the collapsing nephropathy type is characterized by a rapid evolution to chronic renal failure.

Clinical Case: a four-year-old boy presented with an irrelevant past history; eight months before admission he developed idiopathic nephrotic syndrome.