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Disease Profile

Nonalcoholic steatohepatitis

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

Unknown

Age of onset

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ICD-10

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Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

Non-alcoholic steatohepatitis; NASH; Non-alcoholic fatty liver disease

Summary

Nonalcoholic steatohepatitis, or NASH, is a common, often “silent” liver disease. It resembles alcoholic liver disease, but occurs in people who drink little or no alcohol. The major feature in NASH is fat in the liver, along with inflammation and damage. Most people with NASH feel well and are not aware that they have a liver problem. Nevertheless, NASH can be severe and can lead to cirrhosis, in which the liver is permanently damaged and scarred and no longer able to work properly. NASH most often occurs in people who are middle aged and overweight or obese. Affected individuals may also have elevated levels of blood lipids (such as cholesterol and triglycerides) and many have diabetes or prediabetes. Treatment is centered around working towards a healthy lifestyle, including weight reduction, dietary modification, increased activity and avoidance of alcohol and unnecessary medications. The underlying cause of NASH remains unclear.[1]

Cause

The underlying cause of NASH remains unclear. It most often occurs in persons who are middle-aged and overweight or obese. Many patients with NASH have elevated blood lipids, such as cholesterol and triglycerides, and many have diabetes or prediabetes. However, not every obese person or every patient with diabetes has NASH. Furthermore, some patients with NASH are not obese, do not have diabetes, and have normal blood cholesterol and lipids. NASH can occur without any apparent risk factor and can even occur in children.[1]

While the underlying reason for the liver injury that causes NASH is not known, several factors are possible candidates:[1]

  • insulin resistance
  • release of toxic inflammatory proteins by fat cells (cytokines)
  • oxidative stress (deterioration of cells) inside liver cells

Diagnosis

NASH is usually first suspected when elevations are noted in liver tests that are included in routine blood test panels. These may include alanine aminotransferase (ALT) or aspartate aminotransferase (AST). When further evaluation shows no apparent reason for liver disease (such as medications, viral hepatitis, or excessive use of alcohol) and when x-rays or imaging studies of the liver show fat, NASH is suspected. The only way to definitely diagnosis NASH and separate it from simple fatty liver is through a liver biopsy. For a liver biopsy, a needle is inserted through the skin to remove a small piece of the liver. NASH is diagnosed when examination of the tissue with a microscope shows fat along with inflammation and damage to liver cells. If the tissue shows fat without inflammation and damage, simple fatty liver or NAFLD is diagnosed. An important piece of information learned from the biopsy is whether scar tissue has developed in the liver. Blood tests and scans cannot reliably provide this information at this time.[1]

Treatment

Currently, there are no specific therapies for NASH. The most important recommendations given to persons with this disease are to:[1]

  • reduce their weight (if obese or overweight)
  • follow a balanced and healthy diet
  • increase physical activity
  • avoid alcohol
  • avoid unnecessary medications

These are standard recommendations, but they can make a difference. They are also helpful for other conditions, such as heart disease, diabetes, and high cholesterol.[1]

Individuals with other medical conditions (diabetes, high blood pressure, or elevated cholesterol) should be treated with medication as advised by their physician.[1]

Some new treatment options are now being studied in clinical trials. These include the use of antioxidants (such as vitamin E, selenium, and betaine) and some newer antidiabetic medications (metformin, rosiglitazone, and pioglitazone) which treat insulin resistance.[1]

Organizations

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Providing General Support

    Learn more

    These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

    Where to Start

      In-Depth Information

      • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
      • PubMed is a searchable database of medical literature and lists journal articles that discuss Nonalcoholic steatohepatitis. Click on the link to view a sample search on this topic.

        References

        1. Nonalcoholic Steatohepatitis. National Digestive Diseases Information Clearinghouse (NDDIC). 2006; https://digestive.niddk.nih.gov/ddiseases/pubs/nash/.

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