Updated: 12/16/2021

Albinism

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  • Snapshot
    • A 5-year-old girl presents to her primary care physician's office for counseling. She was recently diagnosed with type 2 oculocutaneous albinism based on genetic studies and clinical exam. While her skin is not completely white, it is pink and her hair is light-colored. She is counseled about wearing sunscreen, sunglasses, and sun protective clothes whenever she could be exposed to the sun, due to the increased risk of skin cancer.
  • Introduction
    • Clinical definition
      • hereditary defect in pigmentation
      • two most common types of albinism affecting the skin (oculocutaneous albinism)
        • type 1, known as tyrosinase-negative albinism
          • caused by mutations in tyrosinase gene
          • ↓ or complete inability to produce melanin
        • type 2, known as tyrosinase-positive albinism
          • the most common type in the world
          • defect in tyrosinase transporter
          • ↓ melanin in skin
          • less severe than type 1
      • other variants include ocular albinism, which affects only the eyes
    • Genetics
      • inheritance pattern
        • autosomal recessive
      • mutations
        • type 1
          • chromosome 11
          • gene encoding tyrosinase
        • type 2
          • chromosome 15
          • OCA2 gene
          • encodes small molecule transporters involved in transport of tyrosinase
    • Associated conditions
      • skin cancer
  • ETIOLOGY
    • Pathogenesis
      • normal number of melanocytes
      • ↓ production of melanin
      • ↓ tyrosinase activity or defective tyrosine transport
        • recall that melanin is formed from tyrosine
  • Presentation
    • Symptoms
      • may have ocular symptoms, such as photophobia or blurry vision
    • Physical exam
      • type 1 (more severe)
        • skin
          • white hair without any pigment
          • white or pink skin color
          • blue eyes
          • pink-red nevi
          • solar keratosis
        • ocular
          • impaired visual acuity
          • nystagmus
          • strabismus
      • type 2 (less severe)
        • pink to cream skin color
        • yellow/brown hair (not white hair)
        • blue to yellow/brown irides
        • pigmented nevi
        • freckles
  • Studies
    • Labs
      • genetic testing to confirm diagnosis
  • Differential
    • Vitiligo
  • Treatment
    • Conservative
      • sunscreen, sunglasses, and avoid sun exposure
        • indication
          • for all patients in an attempt to prevent skin cancers or skin burns
    • Operative
      • vision correction surgery
        • may be indicated in cases of severe nystagmus
  • Complications
    • Skin cancer
    • Severe sunburns
  • Prognosis
    • Patients generally live normal lives but are at increased risk for skin cancer
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