Which of the following gene mutations can lead to idiopathic steroid resistant nephrotic syndrome?

A number of proteins have been identified that are components of the cell membrane or actin cytoskeleton of the podocyte. These include nephrin (NPHS1), a-actinin-4, podocin (NPHS2), CD2AP, Wilms tumor suppressor (WT1), and TRPC6. Mutations in the genes for these proteins, occurring in autosomal dominant and recessive patterns, have been associated with steroid-resistant nephrotic syndrome and biopsy-proven FSGS. Ref: Gipson D.S., Trachtman H (2009). Chapter 25. Focal Segmental Glomerulosclerosis. In Lerma E.V., Berns J.S., Nissenson A.R. (Eds), CURRENT Diagnosis & Treatment: Nephrology & Hypeension.