Mucolipidosis type IV is an inherited disorder characterized by delayed development and vision impairment that worsens over time.
People with typical mucolipidosis type IV have delayed development of mental and motor skills (psychomotor delay). Motor skills include sitting, standing, walking, grasping objects, and writing. Mutations in the MCOLN1 gene cause mucolipidosis type IV. This gene provides instructions for making a protein called mucolipin-1. This protein is located in the membranes of lysosomes and endosomes, compartments within the cell that digest and recycle materials. While its function is not completely understood, mucolipin-1 plays a role in the transport (trafficking) of fats (lipids) and proteins between lysosomes and endosomes.
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations.