TPP1 and Duchenne muscular dystrophy: In the case of parents with a living child with CLN2 disease, perceptions of their child’s HRQoL may be unduly influenced by their own coping strategies, such as the extent of their acceptance or denial of their child’s illness (a feature observed in studies of parent proxy reports of HRQoL in children with Duchenne Muscular Dystrophy) [39, 40].