His renal disease was likely related to the underlying WAS mutation since WAS variants with increased IgA and impaired renal function have been reported [40], but his recurrent BKV infection and associated nephropathy suggest impaired immunological function, related to the XLT, which coupled with transplant immunosuppression is likely responsible for a profound immune compromise, and recurrent loss of allografts. The gene discussed is WAS; the disease is kidney disorder.