Custom-designed multiple ligation-dependent probe amplification (MLPA, MRC Holland) validated the array CGH findings and suggested the prevalence of duplications involving PPP2R3B to be 5% of the total cohort of 125 individuals with CMN (Fig. 1c, d), but was not as robust as CGH or NGS for duplication discovery. The gene discussed is PPP2R3B; the disease is congenital mesoblastic nephroma.