Impaired executive functions in Duchenne muscular dystrophy in a Brazilian cohort

Duchenne Muscular Dystrophy (DMD) is a severe, progressive neuromuscular disorder caused by mutations in the DMD gene which codes for dystrophin and is associated with a wide spectrum of developmental cognitive disabilities. Here, a cohort of Brazilian DMD and healthy boys (N = 62) was recruited to investigate the link between mutations on the DMD gene and spatial working memory, associative learning, set-shifting, and planning performance. The findings showed that executive functioning was significantly affected by the absence of the full-length DMD gene product Dp427. Although a larger cohort is needed to confirm initial findings, mutations on the dystrophin gene upstream exon 45 had little impact, while mutations downstream exon 45, especially affecting the expression of the DMD gene product Dp140 and Dp71, led to severe executive dysfunction. The mapping of neurocognitive-genetic associations in DMD is essential to the understanding of developmental disorders and their relationship with mental retardation and the design of effective gene therapies targeting the restoration of DMD gene products, especially the smaller ones.