Disorders of ornithine metabolism

This code signifies a group of rare genetic conditions affecting the body's ability to process ornithine, an amino acid involved in the urea cycle. These disorders lead to the accumulation of ornithine and other related metabolites, primarily impacting neurological and ocular function. The most common manifestation is gyrate atrophy of the choroid and retina.

Assign this code when documentation specifies a diagnosis of a disorder of ornithine metabolism, such as gyrate atrophy. This diagnosis is typically confirmed through genetic testing, elevated ornithine levels in blood or urine, and characteristic ophthalmological findings. Use this code when the patient presents with symptoms like progressive vision loss, night blindness, or muscle weakness, and diagnostic workup confirms an ornithine metabolism defect.

• Always review the physician's documentation for specific details regarding the type of ornithine metabolism disorder.
• Remember the Excludes1 note: never code this alongside hereditary choroidal dystrophy (H31.2-), as gyrate atrophy is a specific type of choroidal dystrophy caused by an ornithine metabolism disorder.
• Consider sequencing this code as the primary diagnosis when it is the main reason for the encounter, especially for diagnostic workup or management of the metabolic condition.