Mucolipidosis Type IV (MCOLN1), 2 Variants

Background information for Mucolipidosis, Type IV (MCOLN1), 2 Variants:
Characteristics: Mucolipidosis type IV is characterized by early onset of severe psychomotor delay and progressive visual impairment due to corneal clouding and retinal degeneration. Affected individuals may occasionally learn to say a few words or walk independently. While most affected individuals remain neurologically static until age 30, about 15 percent will display neurological degeneration.
Incidence: 1 in 63,000 Ashkenazi Jewish individuals.
Inheritance: Autosomal recessive.
Cause: MCOLN1 pathogenic variants.
Variants Tested: g.511_6943del and c.406-2A>G.
Clinical Sensitivity: 95 percent in Ashkenazi Jewish individuals, 6 to 10 percent in other ethnicities.
Methodology: Polymerase chain reaction (PCR) and fluorescence monitoring.
Analytical Sensitivity and Specificity: Greater than 99 percent.
Limitations: Variants other than g.511_6943del and c.406-2A>G will not be detected.  Diagnostic errors can occur due to rare sequence variations.

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.