The incidence of nonalcoholic fatty liver disease (NAFLD) has been rapidly rising worldwide, with many healthcare providers expressing concern. Because of this rapid growth – and simultaneous problems with underdiagnosis – more research has centered around NAFLD, its underlying causes, and what can be done to address it. According to VA News, from the U.S. Department of Veteran Affairs, the Million Veteran Program study sought to better understand some of these underlying causes. Through this study, researchers uncovered 77 locations on the human genome which impact NAFLD risk. 

The study, published in Nature Genetics, sourced genomic data from over 90,000 individuals with chronically elevated ALT levels. Additionally, researchers sourced data from 130,000 control individuals. Next, the researchers performed a genetic analysis. During the study, they found 77 genomic locations – across those of various ethnic backgrounds – which caused heightened ALT elevation. Since increased ALT is heavily associated with NAFLD, these genomic alterations or locations could increase NAFLD risk. Perhaps more interestingly, 25 of these locations had never previously been associated with NAFLD or high ALT levels. One specific location affected only those of European background, and two specific locations affected only those with African backgrounds. 

Moving forward, scientists can now approach research with a new understanding of the potential genetic implications and drivers of NAFLD. More so, researchers hope to be able to build a predictive model which can contribute to an easier and more efficient diagnostic process. 

About Nonalcoholic Fatty Liver Disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) refers to a condition in which excess fat accumulates in the liver of those who do not drink or drink very little. NAFLD encompasses both simple fatty liver and nonalcoholic steatohepatitis (NASH). An estimated 25% of people in the world have NAFLD; researchers estimate that 34% of people will have this condition in the US alone over the next 10 years. Risk factors include obesity, high blood fat levels, high cholesterol levels, high blood sugar, sleep apnea, metabolic syndrome, an underactive thyroid or pituitary gland, older age, polycystic ovary syndrome (PCOS), and type 2 diabetes. Typically, those with NAFLD may not show symptoms, or may experience light symptoms such as fatigue and upper right abdominal pain. As the condition progresses, or proceeds to NASH, symptoms can (but do not always) include:

• Abdominal swelling
• Enlarged spleen and blood vessels
• Reddened palms
• Jaundice (yellowing of the skin, eyes, and mucous membranes) 
• Liver cirrhosis (complication)
• Cardiovascular disease (complication)
• Liver cancer or failure (complication)