SPG7 and mucolipidosis: Since homozygous or biallelic mutations of PGN are responsible respectively for neuronal ceroid lipofuscinosis type 11 and for the mucolipidosis subtypes, characterized by multiple lysosomal effects, dose effects of heterozygous gene variants in causation of diverse neuropsychiatric diseases is clearly established (Huin et al., 2020; Raza et al., 2016).