This article is more than 5 years old. Information may no longer be current.

Researchers find hepatic steatosis, fibrosis are heritable traits

Researchers from University of California San Diego found that hepatic steatosis and hepatic fibrosis were heritable traits among twins, according to published findings.

“This study demonstrates that hepatic fibrosis and hepatic steatosis are heritable,” Rohit Loomba, MD, MHSc, of the NAFLD Translational Research Unit, University of California San Diego, told Healio.com/Hepatology. “This is the first study to document that the heritability of hepatic fibrosis is approximately 50%.”

Rohit Loomba

To determine any heritability of hepatic steatosis and hepatic fibrosis, Loomba and colleagues conducted a cross‐sectional analysis of a community-dwelling twin cohort; preliminary data was presented at the International Liver Congress earlier this year. Sixty pairs of twins (n = 120; 42 monozygotic, 18 dizygotic) were included and all underwent advanced magnetic resonance imaging of the liver between January 2012 and January 2015. MRI was used to quantify hepatic steatosis through the determination of proton‐density fat fraction. In addition, magnetic resonance elastography measured liver stiffness, which was then used to determine liver fibrosis.

Overall, 21.7% of the twins had NAFLD (n = 26). Hepatic steatosis correlated between the monozygotic twins (r² = 0.7; P < .0001). However, the correlation was not observed among the dizygotic twins (r² = 0.36; P = .2). In addition, level of liver fibrosis correlated between the monozygotic twins (r² = 0.48, P < .002) and not the dizygotic twins (r² = 0.12; P = .7).

Multivariable analyses showed that the heritability of hepatic steatosis was 0.52 (95% CI, 0.31-0.73) and hepatic fibrosis was 0.5 (95% CI, 0.28- 0.72), after adjusting for age, sex and ethnicity.

“Hepatic steatosis is a key early event in the development of NAFLD, whereas hepatic fibrosis is a later event that has prognostic significance in predicting long-term outcomes related to liver disease,” the researchers wrote. “Recent studies have suggested that there is a significant genetic association with presence of hepatic steatosis.”

According to a press release, the researchers are expanding the research to include the role of the microbiome, which also indicates heritability.

“It is plausible that cirrhosis due to nonalcoholic fatty liver disease may run in families as suggested by previous studies showing familial aggregation of NAFLD. This is the dawn of the new era to tease out genetic and environmental determinants of hepatic fibrosis,” Loomba added. – by Melinda Stevens

Disclosures: The researchers report no relevant financial disclosures.