Tyrosinemia type II is an autosomal recessive condition with onset between ages 2 and 4 years, when painful circumscribed calluses develop on the pressure points of the palm of the hand and sole of the foot.

[4]: 512 Type II tyrosinemia is caused by a deficiency of the enzyme tyrosine aminotransferase (EC 2.6.1.5), encoded by the gene TAT.

Symptoms often begin in early childhood and include excessive tearing, abnormal sensitivity to light (photophobia), eye pain and redness, and painful skin lesions on the palms and soles.

About half of individuals with type II tyrosinemia are also mentally disabled.

[5] Diagnosis is made based on elevated plasma tyrosine level with skin or eye lesions.