Ordering Recommendation

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

Mnemonic
PNPLA3
Methodology

Polymerase Chain Reaction/Fluorescence Monitoring

Performed

Sun-Sat

Reported

7-10 days

New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
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

Remarks
Stability

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

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 US.
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 followed by high-resolution melt analysis.
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