Ordering Recommendation

Carrier screening or diagnostic testing for mucolipidosis type IV for individuals of Ashkenazi Jewish descent.

Mnemonic
MCOLN1
Methodology

Polymerase Chain Reaction/Fluorescence Monitoring

Performed

Tue, Fri

Reported

5-10 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation

Transport 3 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Specimens collected in sodium heparin or lithium heparin tubes.

Remarks
Stability

Ambient: 72 hours; Refrigerated: 2 weeks; Frozen: 1 month

Reference Interval

By report

Interpretive Data

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.

Compliance Category

Laboratory Developed Test (LDT)

Note
Hotline History
N/A
CPT Codes

81290

Components
Component Test Code* Component Chart Name LOINC
0051450 Mucolipidosis IV (MCOLN1), Allele 1 34658-5
0051451 Mucolipidosis IV (MCOLN1), Allele 2 34658-5
0051452 Mucolipidosis IV (MCOLN1), Interp 46965-0
2001329 Mucolipidosis IV (MCOLN1), Specimen 31208-2
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Aliases
Mucolipidosis Type IV (MCOLN1), 2 Variants