Mucolipidosis type 4
Overview
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.
Symptoms
- Mental retardation
- Cloudy corneas
- Reduced muscle tone
- Retina impairment
- Psychomotor impairment
Causes
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. Mucolipin-1 appears to be important for the development and maintenance of the brain and retina. In addition, this protein is likely critical for normal functioning of the cells in the stomach that produce digestive acids.
Most mutations in the MCOLN1 gene result in the production of a nonfunctional protein or prevent any protein from being produced. A lack of functional mucolipin-1 impairs transport of lipids and proteins, causing these substances to build up inside lysosomes. Conditions that cause molecules to accumulate inside the lysosomes, including mucolipidosis type IV, are called lysosomal storage disorders. Two mutations in the MCOLN1 gene account for almost all cases of mucolipidosis type IV in people with Ashkenazi Jewish ancestry. It remains unclear how mutations in this gene lead to the signs and symptoms of mucolipidosis type IV.
Read more about the MCOLN1 gene.
Diagnosis
- High Cholesterol: Home Testing:
- Home Cholesterol Tests
- Home Triglycerides Tests
- Home Blood Pressure Tests
- High Blood Pressure: Home Testing
- Home Blood Pressure Monitors
- Home Heart Tests
- Heart Health: Home Testing:
- Heart Rate Monitors
- Irregular Heartbeat Detection
- Heart Electrocardiogram (ECG)