Disorders of aromatic amino-acid metabolism (E70)

Browse all the diagnosis codes used for disorders of aromatic amino-acid metabolism (e70). For easy navigation, the diagnosis codes are sorted in alphabetical order and grouped by sections. Each section is clearly marked with its description, and the corresponding three-digit code range. This format makes it simple to browse diagnosis codes in this chapter or section and find what you're looking for. We've also added green checkmark icons to label billable codes, and red warning icons for non-billable ones. This makes it easy to identify which codes can be billed.

Clinical Information

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.