Alkaptonuria. The urine in the glass B has been for 24 hours and has become dark. Alajoulin OA, 2015. Openi. CC BY NC SA 3.0

Definition

Alkaptonuria is a rare, hereditary disease that causes the amino acids phenyl-alanine and tyrosine not to degrade and accumulate in cartilage and heart valves.

Symptoms of Alkaptonuri

• Striking brown urine from childhood on
• Brown pigment patches on ear cartilage and eyes (on sclera)
• Symptom debut from 30 years of age
• Increasing pain
  • Back
  • Hips
  • Knees
• Osteoarthritis (Ochronose)
• Late injuries (Achilles tendon rupture)
• Osteoporosis
• Cardiovascular disease (aortic and mitral valve)
• Stone formation
  • Nephrolithiasis
  • Gallstones
  • Salivary gland stone
• "White intervertebral Discs" (calcified discs) on X-rays
• "Black Invertebrates" by DEXA scan (osteoporosis assessment)

Diagnosis

• Urine:
  • The amount of homogenticic acid is determined by chromatography after urin collection over 24 hours
• Genetic testing

Treatment

• No healing treatment
• Unsafe effect, but high doses of ascorbic acid (vitamin C) and diet that reduces the intake of phenylalanine and tyrosine (guidance via nutritionist) are attempted.

Prognosis

• Pain and reduced quality of life
• Often need for joint prostheses
• Not shortened life span

References

• Mistry JB, Bukhari M, Rare diseases 2013
• Wikipedia