In a groundbreaking study, researchers at the Mayo Clinic have identified a rare gene mutation responsible for triggering fatty liver disease, challenging previous assumptions that the condition primarily stemmed from a combination of genetic predisposition and lifestyle factors. Findings published in Hepatology reveal that a single inherited mutation can significantly influence the onset of this disease.
The research team pinpointed the variant to the MET gene, which is crucial for liver repair and fat metabolism. Dysfunction in this gene leads to fat accumulation within liver cells, resulting in inflammation. Over time, this inflammation can progress to fibrosis and scarring, potentially leading to cirrhosis and severe liver damage.
Currently, metabolic dysfunction-associated steatotic liver disease affects approximately one-third of adults globally. Its more severe counterpart, metabolic dysfunction-associated steatohepatitis, is anticipated to become a leading cause of cirrhosis and the primary reason for liver transplants in the near future.
Lead author Dr. Filippo Pinto e Vairo, medical director of the Program for Rare and Undiagnosed Diseases at Mayo Clinic's Center for Individualized Medicine, emphasized that this discovery sheds light on how rare genetic variants can trigger common diseases, offering new insights into disease mechanisms and potential therapeutic avenues.
Genetic Clue from a Family Case
The investigation began with a genomic analysis of a woman and her father, both diagnosed with metabolic dysfunction-associated steatohepatitis, yet lacking common risk factors like diabetes or high cholesterol. This prompted researchers to perform an extensive genetic examination across over 20,000 genes, leading to the identification of a significant alteration in the MET gene.
Collaborating with experts from the Medical College of Wisconsin, the team confirmed that this mutation disrupts a vital biological process. A single letter change in the DNA sequence obstructs the liver's ability to process fat, marking this rare genetic variant as unprecedented in scientific literature.
Dr. Raul Urrutia, who led the collaborative effort, noted that this study illustrates how rare diseases often remain hidden within complex disorders, highlighting the power of individualized medicine in uncovering them and paving the way for advanced diagnostics and targeted therapies.
Large Genomic Study Identifies Similar Variants
To assess the prevalence of this mutation, researchers analyzed data from Mayo Clinic's Tapestry study, which aims to uncover genetic factors influencing various diseases. This initiative has examined DNA from over 100,000 participants, creating a robust genomic database.
Among nearly 4,000 adults with metabolic dysfunction-associated steatotic liver disease in the Tapestry study, around 1% carried rare variants in the MET gene, with nearly 18% of these variants located in the same critical region as the initial family finding. This reinforces the gene's significance in liver disease.
Dr. Konstantinos Lazaridis, another lead author, highlighted the potential impact of these findings on countless individuals worldwide at risk for this condition, reiterating the importance of the Tapestry study in uncovering hidden genetic factors.
Advancing Genomic Medicine
This discovery underscores the increasing role of genomic medicine in clinical practice at Mayo Clinic. Since its inception in 2019, the Program for Rare and Undiagnosed Diseases has facilitated comprehensive genomic testing for over 3,200 patients, collaborating with nearly 300 clinicians to provide precision diagnostics for challenging conditions, including rare liver diseases.
Future research will explore how these findings can inform targeted treatment strategies and enhance diagnostic and management approaches for metabolic dysfunction-associated steatotic liver disease.