What is Mucolipidosis III Gamma? Mucolipidosis III gamma is an inherited, lysosomal storage disorder. Mucolipidosis III gamma is caused by harmful changes (mutations) in the GNPTG gene. The symptoms associated with mucolipidosis III gamma are caused by a buildup of harmful substances in the cells of the body. Mucolipidosis III gamma is primarily associated with progressive skeletal, joint, and connective-tissue abnormalities. Symptoms typically begin in early childhood and most commonly include joint stiffness, loss of flexibility, and pain. The fingers, shoulders, and hips are particularly affected. Pain, numbness, and tingling in the hand and arm (carpal tunnel syndrome) is common in children and young adults. Other skeletal abnormalities include slow growth; short height; low bone mineral density (osteoporosis) that may cause an increased risk for fractures; curvature of the spine (scoliosis); and gradual, mild coarsening of facial features. Additionally, symptoms may include heart-valve abnormalities; problems with the ribs, which may impact lung function; and clouding of the cornea in the eyes. Many affected individuals will develop thickened skin and facial features (broad nose, large tongue, and thick lips). The majority of affected individuals have intellectual ability within the normal range, but mild intellectual disability has been reported. How common is Mucolipidosis III Gamma? Mucolipidosis III gamma has been reported in fewer than 100 patients worldwide. The exact incidence is unknown. How is Mucolipidosis III Gamma treated? There is no cure for mucolipidosis III gamma, and there are no known treatments to slow the limitations caused by progressive stiffness of the joints. Treatment may include pain management and/or physical therapy. Surgery may be done if hip replacement or heart valve replacement is necessary. What is the prognosis for an individual with Mucolipidosis III Gamma? Mucolipidosis III gamma is a slowly progressive condition that causes significant joint pain and problems with mobility. Many individuals affected with mucolipidosis III gamma have survived into adulthood, but prognosis is difficult to predict due to the rarity of the condition. Other names formucolipidosis III gamma ML IIIC MLIII Mucolipidosis IIIC References Liu et al., 2014, Gene, 535(2):294-8, PMID: 24316125 Nampoothiri et al., 2019, Clin Dysmorphol, 28(1):7-16, PMID: 30507725 OMIM: Online Mendelian Inheritance in Man, OMIM [252605], 2016, https://www.omim.org/entry/252605 Persichetti et al., 2009, Hum Mutat, 30(6):978-84, PMID: 19370764 Raas-Rothschild et al., 2019, http://www.ncbi.nlm.nih.gov/books/NBK24701/