Mucolipidosis type IV

A rare genetic disorder affecting lysosomal storage

Classification
External resources

Mucolipidosis type IV (ML IV) is a rare lysosomal storage disorder characterized by the accumulation of lipids and mucopolysaccharides in the body's cells. It is an autosomal recessive disorder, meaning that an individual must inherit two copies of the defective gene, one from each parent, to be affected by the disease.

Genetics

Autosomal recessive inheritance pattern

ML IV is caused by mutations in the MCOLN1 gene, which encodes the protein mucolipin-1. This protein is involved in the regulation of lysosomal function and membrane trafficking. Mutations in the MCOLN1 gene lead to the dysfunction of lysosomes, resulting in the accumulation of undigested materials within cells.

Clinical Features

Individuals with ML IV typically present with developmental delay, intellectual disability, and motor skill impairment. Other common symptoms include:

• Corneal clouding
• Retinal degeneration
• Strabismus
• Hypotonia
• Gastroesophageal reflux disease

Diagnosis

The diagnosis of ML IV is based on clinical evaluation, laboratory testing, and genetic testing. Laboratory tests may reveal elevated levels of certain lipids and mucopolysaccharides in the blood or urine. Genetic testing can confirm the presence of mutations in the MCOLN1 gene.

Management

There is currently no cure for ML IV, and treatment is primarily supportive. Management strategies may include:

• Physical therapy to improve motor skills
• Occupational therapy to assist with daily activities
• Speech therapy to address communication difficulties
• Regular ophthalmologic evaluations to monitor vision

Prognosis

The prognosis for individuals with ML IV varies. While some individuals may have a relatively stable course, others may experience progressive neurological decline. Life expectancy can be reduced, but supportive care can improve quality of life.

Related pages

• Lysosomal storage disorder
• Autosomal recessive disorder
• Genetic disorder