Type of disease: Rare conditions
Mucolipidosis type 3 (ML 3) is an inherited metabolic disease. Metabolism is the body’s process of making and using energy in order to properly function. ML 3 is characterized by problems in the breakdown of fats called microlipids. The disease typically appears around age 3.
There are two categories of ML 3: alpha/beta and gamma. The categories have similar symptoms including slowed physical growth, short height, stiff joints, clouding of the cornea (covering of the eye), heart valve abnormalities, and skeletal abnormalities. Additional, many individuals eventually develop osteoporosis, which involves the weakening of the bones and increases the chance of developing bone fractures. Both categories of the condition are also linked with developmental and mental delays, including mild intellectual disabilities and learning problems. Individuals with this condition usually survive into adulthood, but may not live as long as individuals without the condition.
ML 3 is linked to changes in the GNPTG gene. ML 3 is inherited in an autosomal recessive manner, meaning an individual must have two copies of the changed gene or mutation that causes the condition. A person with one changed gene would be a carrier of the condition but usually will not have any symptoms. If both parents are carriers of ARC syndrome, each child has a one in four chance (25%) of having the disease.
ML 3 can be diagnosed by testing the blood or urine for high levels of microlipids, in addition to looking at medical history, symptoms, and performing a physical exam. Genetic tests may also be done in order to look for changes in the GNPTG gene.
Treatment for individuals with ML 3 usually includes physical therapy, medications to relieve associated pain, and specific treatment for osteoporosis later in life. If you or a family member has been diagnosed with mucolipidosis type 3, talk to your doctor about the most current treatment options.