Richner-Hanhart Syndrome | Tyrosinemia type II | Corneal dystrophy

  • AKA Tyrosinemia type II
  • AR
  • TAT gene → tyrosine aminotransferase
  • Increased tyrosine in all tissues, including crystals in cornea
  • Focal to diffuse painful PPK, hyperkeratotic plaques elbows/knees
  • Cutaneous signs
    • Palmar hyperkeratosis
    • Plantar hyperkeratosis
  • Ocular signs
    • Corneal ulcers
    • Corneal opacities
  • Intellectual disability
  • Severe keratitis (pseudoherpetic) - photophobia, ulceration, blindness
  • Treatment
    • Early initiation of low phenylalanine/tyrosine diet → clear cutaneous/ocular complications
    • May delay/prevent further cognitive impairment