Ordering Recommendation

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

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. Frozen specimens in glass collection tubes.

Remarks
Stability

Ambient: 72 hours; Refrigerated: 1 week; 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.

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.

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
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

Mucolipidosis Type IV (MCOLN1), 2 Variants