Screen for genetic susceptibility to non-alcoholic fatty liver disease and cirrhosis progression in alcoholic liver disease.
- Patient Preparation
- Lavender (EDTA).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 1 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Plasma or serum. Specimens collected in sodium heparin or lithium heparin
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: unacceptable
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.
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.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
|Component Test Code*||Component Chart Name||LOINC|
- Hepatic steatosis genotyping