2025 ICD-10-CM code E72.4
(Active) Effective Date: N/A Metabolic disorders - Disorders of urea cycle metabolism Endocrine, Nutritional and Metabolic Diseases (E00-E89) Feed
Disorders of ornithine metabolism, including hyperammonemia-hyperornithinemia-homocitrullinuria (HHH) syndrome, ornithinemia, and ornithine transcarbamylase deficiency.
Medical necessity for services related to E72.4 should be established by documenting the presence of signs, symptoms, or laboratory findings consistent with ornithine metabolism disorders.The rationale for diagnostic testing, including genetic testing, should be clearly documented.The need for specific treatments, such as medications, dietary management, or other interventions, should be justified based on the patient's clinical condition and the severity of the disorder.The medical necessity for ongoing monitoring and follow-up care should also be documented.
Clinicians responsible for diagnosing and managing patients with E72.4 include geneticists, metabolic specialists, neurologists, hepatologists, and pediatricians/neonatologists.Diagnosis often involves blood and urine tests to assess levels of ammonia, amino acids, and other metabolites. Genetic testing is crucial for confirming the specific disorder. Treatment strategies vary depending on the specific condition but may include dietary restrictions (low-protein, low-ornithine), medications to reduce ammonia levels, and, in severe cases, hemodialysis or liver transplantation.Supportive care is essential and may involve managing neurological complications, developmental delays, and other associated symptoms.
In simple words: Ornithine metabolism disorders disrupt the body's process of removing harmful ammonia. This can lead to a variety of problems, including HHH syndrome, high ornithine levels in the blood (ornithinemia), and a deficiency in a specific enzyme called ornithine transcarbamylase.
This code encompasses several disorders affecting ornithine metabolism, a crucial part of the urea cycle responsible for removing ammonia from the body.These disorders include: Hyperammonemia-Hyperornithinemia-Homocitrullinuria (HHH) syndrome (Types I and II): Caused by mutations in the SLC25A15 gene, affecting the mitochondrial ornithine transporter ORNT1, which leads to the accumulation of ornithine, ammonia, and homocitrulline in the body. Ornithinemia: Elevated levels of ornithine in the blood. Ornithine Transcarbamylase Deficiency: An X-linked genetic disorder caused by mutations in the OTC gene, leading to a deficiency of the enzyme ornithine transcarbamylase. This deficiency impairs the body's ability to convert ammonia to urea, resulting in a toxic buildup of ammonia.
Example 1: A newborn male presents with lethargy, poor feeding, and vomiting a few days after birth.Blood tests reveal elevated ammonia levels, and genetic testing confirms ornithine transcarbamylase deficiency., A 5-year-old girl exhibits developmental delays and learning difficulties. After experiencing an episode of confusion and vomiting, she undergoes metabolic testing, which reveals elevated levels of ornithine, ammonia, and homocitrulline, leading to a diagnosis of HHH syndrome., A 30-year-old woman experiences recurrent episodes of nausea, vomiting, and headaches, particularly after consuming protein-rich meals. Following a thorough evaluation, she is diagnosed with a mild form of ornithine transcarbamylase deficiency, which was previously asymptomatic.
Documentation should include detailed clinical findings, including symptoms, onset, and severity.Laboratory results, such as ammonia, amino acid, and other metabolite levels, are crucial. Genetic testing reports confirming the specific diagnosis should be included.Treatment plans, including dietary restrictions, medications, and any procedures like hemodialysis or liver transplant, should be documented. Ongoing monitoring of the patient's condition and response to treatment should be recorded.
- Specialties:Genetics, metabolic disorders, neurology, hepatology, pediatrics, neonatology
- Place of Service:Inpatient Hospital, Outpatient Hospital, Office, Independent Clinic, Federally Qualified Health Center