A very rare lysosomal disease, that has most often been observed in the Middle East, characterized by a progressive slowing of the growth rate in early childhood; stiffness and pain in shoulders, hips, and finger joints; a gradual, mild coarsening of facial features; and by a slower progression, milder clinical course and longer life expectancy than that seen in mucolipidosis II and mucolipidosis III alpha/beta. Cognitive function is normal or only slightly impaired and retinitis pigmentosa has been reported in a few patients. Many survive into early adulthood, but ultimately succumb to cardiorespiratory insufficiency. The disease is GNPTG-mucolipidosis (MONDO_0009652, a Monarch Disease Ontology entry). Also known as: ML 3 gamma, ML III gamma, mucolipidosis type 3 gamma, mucolipidosis type III gamma.