Oculocutaneous albinism
Oculocutaneous albinism is an autosomal recessive group of disorders with a normal melanocyte number but reduced melanin production from decreased tyrosinase activity or defective tyrosine transport, producing congenital hypopigmentation of skin and hair plus infantile nystagmus, photophobia, strabismus, and foveal hypoplasia. There is no treatment that corrects the underlying melanin-pathway defect, so first-line management is lifelong broad-spectrum SPF 30 or higher sunscreen and physical sun protection paired with early vision correction and low-vision rehabilitation.
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What this article covers
- Overview
Definition: oculocutaneous albinism (OCA) is a group of autosomal recessive disorders of melanin synthesis in which the melanocyte number is normal but melanin production is reduced because of…
- Epidemiology
Present from birth or early infancy: hypopigmentation of skin and hair relative to family background is recognized congenitally or in early life, together with the ocular findings.
- Risk factors
Biallelic pathogenic variants in a pigmentation gene: the defining cause, producing decreased tyrosinase activity or defective tyrosine transport in melanocytes.
- Pathophysiology
Normal melanocyte number, deficient melanin output: unlike destructive pigment disorders, the melanocytes themselves are present and intact; they simply cannot manufacture or transport melanin normally.
- Clinical features
Establishing features: congenital or early-life hypopigmentation of the skin and hair relative to family background, together with infantile nystagmus, reduced visual acuity, and photophobia, define the clinical picture.
- Differential diagnosis
Vitiligo: irregular patches of complete depigmentation from autoimmune melanocyte destruction, unlike OCA, in which pigmentation is diffusely reduced from birth with a normal melanocyte number rather than patchy and acquired.
- Diagnosis
The diagnostic basis is clinical recognition confirmed by genetic testing: congenital or early-life hypopigmentation of skin and hair relative to family background, together with infantile nystagmus…
- Management
First, initiate lifelong photoprotection: use shade, densely woven or ultraviolet-protective clothing, a broad-brim hat, ultraviolet-blocking eyewear, and broad-spectrum, water-resistant sunscreen…
- Complications
Cutaneous malignancy: increased lifetime risk of ultraviolet-driven skin cancer from chronically deficient epidermal melanin, including amelanotic melanoma that can be missed without a low biopsy threshold.
- Prognosis
Normal cognition and lifespan in nonsyndromic OCA: the isolated pigmentary and ocular phenotype does not shorten life expectancy or impair cognitive development.
- Prevention
Sunscreen reapplication at least every 2 hours and after swimming or heavy sweating, with SPF 30 or higher and approximately 2 mg/cm2 applied to exposed skin, is the core preventive measure against ultraviolet-driven skin cancer.
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