Oculocutaneous tyrosinosis. Report of two cases in the same family.

Clinical and biochemical evidence of oculocutaneous tyrosinosis, a rare disease due to hepatic soluble tyrosine aminotransferase (STAT) deficiency, was found in a 3 1/2-year-old girl and in her maternal aunt. Different expressivity of this disease, resulting in clinical heterogeneity, is shown to occur commonly according to the cases reported in this as well as in previous studies. The metabolic pathways leading to the unexpected excretion of phenolic acids in urine are reviewed, and the need for early diagnosis and dietary treatment, in order to prevent corneal clouding and brain damage is finally stressed.