Among them, two examples were selected to illustrate age-related differential exon usage: SMIM11A mRNA (Small Integral Membrane Protein 11A, of unknown function) and RXYLT1 mRNA (Ribitol Xylosyltransferase 1, associated with Walker–Wahlburg syndrome and muscular dystrophy–dystroglycanopathy43,44). This evidence concerns the gene RXYLT1 and muscular dystrophy.