Corrigendum: Case Report: Whole-Exome Sequencing With MLPA Revealed Variants in Two Genes in a Patient With Combined Manifestations of Spinal Muscular Atrophy and Duchenne Muscular Dystrophy - Xia, Yu; Feng, Yijie; Xu, Lu; Chen, Xiaoyang; Gao, Feng; Mao, Shanshan (Frontiers in Genetics, 2021)