Downregulation of miRNA-29, -23 and -21 in urine of Duchenne muscular dystrophy patients by Catapano, F, Domingos, J, Perry, M, Ricotti, V, Phillips, L, Servais, LJP, Seferian, A, de Groot, I, Krom, YD, Niks, EH, Verschuuren, JJ, Straub, V, Voit, T, Morgan, J, Muntoni, F