ICD-10-CM Code E72.4

Disorders of ornithine metabolism

Version 2021 Billable Code

Valid for Submission

E72.4 is a billable code used to specify a medical diagnosis of disorders of ornithine metabolism. The code is valid for the fiscal year 2021 for the submission of HIPAA-covered transactions. The ICD-10-CM code E72.4 might also be used to specify conditions or terms like disorder of ornithine metabolism, hyperammonemia, hyperammonemia, hyperornithinemia, hyperornithinemia-hyperammonemia-homocitrullinuria syndrome, ornithine aminotransferase deficiency, etc

Short Description:Disorders of ornithine metabolism
Long Description:Disorders of ornithine metabolism

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code E72.4:

Inclusion Terms

Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
  • Hyperammonemia-Hyperornithinemia-Homocitrullinemia syndrome
  • Ornithinemia (types I, II)
  • Ornithine transcarbamylase deficiency

Type 1 Excludes

Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
  • hereditary choroidal dystrophy H31.2

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code E72.4 are found in the index:


The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Disorder of ornithine metabolism
  • Hyperammonemia
  • Hyperammonemia
  • Hyperornithinemia
  • Hyperornithinemia-hyperammonemia-homocitrullinuria syndrome
  • Ornithine aminotransferase deficiency
  • Ornithine carbamoyltransferase deficiency

Convert E72.4 to ICD-9

  • 270.6 - Dis urea cycle metabol (Approximate Flag)

Code Classification

  • Endocrine, nutritional and metabolic diseases (E00–E90)
    • Metabolic disorders (E70-E88)
      • Other disorders of amino-acid metabolism (E72)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021

Information for Patients

Amino Acid Metabolism Disorders

Metabolism is the process your body uses to make energy from the food you eat. Food is made up of proteins, carbohydrates, and fats. Your digestive system breaks the food parts down into sugars and acids, your body's fuel. Your body can use this fuel right away, or it can store the energy in your body. If you have a metabolic disorder, something goes wrong with this process.

One group of these disorders is amino acid metabolism disorders. They include phenylketonuria (PKU) and maple syrup urine disease. Amino acids are "building blocks" that join together to form proteins. If you have one of these disorders, your body may have trouble breaking down certain amino acids. Or there may be a problem getting the amino acids into your cells. These problems cause a buildup of harmful substances in your body. That can lead to serious, sometimes life-threatening, health problems.

These disorders are usually inherited. A baby who is born with one may not have any symptoms right away. Because the disorders can be so serious, early diagnosis and treatment are critical. Newborn babies get screened for many of them, using blood tests.

Treatments may include special diets, medicines, and supplements. Some babies may also need additional treatments if there are complications.

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Ornithine translocase deficiency Ornithine translocase deficiency is an inherited disorder that causes ammonia and other substances to build up (accumulate) in the blood. Ammonia, which is formed when proteins are broken down in the body, is toxic if the levels become too high. The nervous system is especially sensitive to the effects of excess ammonia.Ornithine translocase deficiency varies widely in its severity and age of onset. Affected infants show signs and symptoms of ornithine translocase deficiency within days after birth. In most affected individuals, however, signs and symptoms of ornithine translocase deficiency do not appear until later in life, with health problems first appearing anytime from childhood to adulthood. Later-onset forms of ornithine translocase deficiency are usually less severe than the infantile form.Infants with ornithine translocase deficiency may lack energy (be lethargic), refuse to eat, vomit frequently, or have poorly controlled breathing or body temperature. Seizures or unusual body movements are common in these individuals. Some people with this condition have intellectual disability or developmental delay, but others have normal intelligence. Severe cases may result in coma.Some people with later-onset ornithine translocase deficiency have episodes of vomiting, lethargy, problems with coordination (ataxia), vision problems, episodes of brain dysfunction (encephalopathy), developmental delay, learning disabilities, or stiffness caused by abnormal tensing of the muscles (spasticity). Affected individuals may have chronic liver problems and mild abnormal bleeding.Individuals with ornithine translocase deficiency often cannot tolerate high-protein foods, such as meat. Occasionally, high-protein meals or stress caused by illness or periods without food (fasting) may cause ammonia to accumulate more quickly in the blood. This rapid increase of ammonia likely leads to the signs and symptoms of ornithine translocase deficiency.While the signs and symptoms of ornithine translocase deficiency can vary greatly among affected individuals, proper treatment can prevent some complications from occurring and may improve quality of life.
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