Disorders of aromatic amino-acid metabolism (E70) ICD-10-CM
The E70 code range covers disorders of aromatic amino-acid metabolism with 34 ICD-10-CM diagnosis codes. 26 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Codes in the E70 Range 34 codes · 26 billable
- E70 Disorders of aromatic amino-acid metabolismNon-billable
- E70.0 Classical phenylketonuria
- E70.1 Other hyperphenylalaninemias
- E70.2 Disorders of tyrosine metabolismNon-billable
- E70.20 Disorder of tyrosine metabolism, unspecified
- E70.21 Tyrosinemia
- E70.29 Other disorders of tyrosine metabolism
- E70.3 AlbinismNon-billable
- E70.30 Albinism, unspecified
- E70.31 Ocular albinismNon-billable
- E70.310 X-linked ocular albinism
- E70.311 Autosomal recessive ocular albinism
- E70.318 Other ocular albinism
- E70.319 Ocular albinism, unspecified
- E70.32 Oculocutaneous albinismNon-billable
- E70.320 Tyrosinase negative oculocutaneous albinism
- E70.321 Tyrosinase positive oculocutaneous albinism
- E70.328 Other oculocutaneous albinism
- E70.329 Oculocutaneous albinism, unspecified
- E70.33 Albinism with hematologic abnormalityNon-billable
- E70.330 Chediak-Higashi syndrome
- E70.331 Hermansky-Pudlak syndrome
- E70.338 Other albinism with hematologic abnormality
- E70.339 Albinism with hematologic abnormality, unspecified
- E70.39 Other specified albinism
- E70.4 Disorders of histidine metabolismNon-billable
- E70.40 Disorders of histidine metabolism, unspecified
- E70.41 Histidinemia
- E70.49 Other disorders of histidine metabolism
- E70.5 Disorders of tryptophan metabolism
- E70.8 Other disorders of aromatic amino-acid metabolismNon-billable
- E70.81 Aromatic L-amino acid decarboxylase deficiency
- E70.89 Other disorders of aromatic amino-acid metabolism
- E70.9 Disorder of aromatic amino-acid metabolism, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the E70 range.
Albinism
General term for a number of inherited defects of amino acid metabolism in which there is a deficiency or absence of pigment in the eyes, skin, or hair.
Albinism, Ocular
Albinism affecting the eye in which pigment of the hair and skin is normal or only slightly diluted. The classic type is X-linked (Nettleship-Falls), but an autosomal recessive form also exists. Ocular abnormalities may include reduced pigmentation of the iris, nystagmus, photophobia, strabismus, and decreased visual acuity.
Albinism, Oculocutaneous
Heterogeneous group of autosomal recessive disorders comprising at least four recognized types, all having in common varying degrees of hypopigmentation of the skin, hair, and eyes. The two most common are the tyrosinase-positive and tyrosinase-negative types.
Piebaldism
Autosomal dominant, congenital disorder characterized by localized hypomelanosis of the skin and hair. The most familiar feature is a white forelock presenting in 80 to 90 percent of the patients. The underlying defect is possibly related to the differentiation and migration of melanoblasts, as well as to defective development of the neural crest (neurocristopathy). Piebaldism may be closely related to WAARDENBURG SYNDROME.
Waardenburg Syndrome
Rare, autosomal dominant disease with variable penetrance and several known clinical types. Characteristics may include depigmentation of the hair and skin, congenital deafness, heterochromia iridis, medial eyebrow hyperplasia, hypertrophy of the nasal root, and especially dystopia canthorum. The underlying cause may be defective development of the neural crest (neurocristopathy). Waardenburg's syndrome may be closely related to piebaldism. Klein-Waardenburg Syndrome refers to a disorder that also includes upper limb abnormalities.
About the E70 Code Range
The ICD-10 code section E70 covers disorders of aromatic amino-acid metabolism, which includes specific metabolic conditions related to amino acids like phenylalanine, tyrosine, histidine, and tryptophan. These codes identify disorders such as phenylketonuria, tyrosinemia, various forms of albinism, and other enzyme deficiencies associated with amino acid processing.
This section helps medical coders correctly classify conditions ranging from E70.0 for classical phenylketonuria (often simply called phenylketonuria) to E70.21 for tyrosinemia, a disorder affecting tyrosine metabolism. Albinism-related codes like E70.3 capture different types including ocular and oculocutaneous albinism, with detailed subcodes such as E70.310 for X-linked ocular albinism. Disorders of histidine and tryptophan metabolism are noted under codes like E70.4 and E70.5, with histidinemia and tryptophanuria as examples. This ICD-10 code section ensures precise identification of these rare enzyme-related metabolic and pigmentary disorders, aiding in targeted diagnosis and treatment decisions.
Questions About This Page
How many billable codes are in the E70 range?
Of the 34 codes in this range, 26 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the E70 range classify?
The range classifies disorders of aromatic amino-acid metabolism. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
