Ordering Recommendation

Screen for genetic susceptibility to non-alcoholic fatty liver disease and cirrhosis progression in alcoholic liver disease.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation
Collect

Lavender (EDTA).

Specimen Preparation

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

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Plasma or serum. Specimens collected in sodium heparin or lithium heparin. Frozen specimens in glass collection tubes.

Remarks
Stability

Ambient: 72 hours; Refrigerated: 1 week; Frozen: 1 month

Methodology

Polymerase Chain Reaction (PCR)/Fluorescence Monitoring

Performed

Sun-Sat

Reported

7-10 days

Reference Interval

Interpretive Data

Background Information for Non-Alcoholic Fatty Liver Disease Susceptibility (PNPLA3) Genotyping:

Characteristics:
Fatty liver disease is the accumulation of excessive triglycerides in the liver that may cause an inflammatory response, which can progress to fibrosis, cirrhosis, and liver cancer. The c.444C>G; p.I148M variant in the PNPLA3 gene confers an increased risk for the onset and progression of non-alcoholic fatty liver disease (NAFLD). This allele also confers an increased risk for the onset and progression of cirrhosis among individuals with alcoholic liver disease.

Incidence: NAFLD occurs in approximately 20-30 percent of individuals in the U.S.

G Allele Frequency: Varies by ethnicity; Latino 0.57, East Asian 0.38, European 0.23, South Asian 0.22, Africans 0.14.

Cause: Risk factors for non-alcoholic fatty liver disease include obesity, diabetes, insulin resistance and genetic risk factors including PNPLA3 c.444C>G; p.I148M.

Inheritance: Multifactorial.

Clinical Sensitivity:
Unknown.

Variant Tested:
 PNPLA3 c.444C>G; p.I148M (rs738409).

Methodology:
Polymerase chain reaction (PCR) and fluorescence monitoring.

Analytical Sensitivity and Specificity:
Greater than 99 percent.

Limitations:
Only the c.444C>G; p.I148M variant in the PNPLA3 gene will be targeted. Diagnostic errors can occur due to rare sequence variations.

Compliance Category

Laboratory Developed Test (LDT)

Note

Hotline History

N/A

CPT Codes

81479

Components

Component Test Code* Component Chart Name LOINC
2014600 PNPLA3 Specimen 31208-2
2014601 PNPLA3 Variant 35474-6
2014602 PNPLA3 Interpretation 50398-7
* 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

  • Hepatic steatosis genotyping
Non-Alcoholic Fatty Liver Disease Susceptibility (PNPLA3) Genotyping