MLIV is an autosomal recessive lysosomal storage disease caused by loss-of-function mutations in the MCOLN1 gene, coding for the potential channel protein mucolipin-1 (TRPML1), resulting in abnormal transport of the lipids to the lysosomes where heterogeneous materials (phospholipids and gangliosides) accumulate [68,69]. This evidence concerns the gene MCOLN1 and lysosomal storage disease.