A child with dendritiform eye lesions and developmental delay.

Area of Science:

• Ophthalmology
• Genetics
• Metabolic Disorders

Background:

• Tyrosinemia Type II (Richner-Hanhart syndrome) is a rare autosomal recessive disorder caused by tyrosine aminotransferase deficiency.
• It can lead to severe oculocutaneous manifestations, including ulcerated keratitis.

Observation:

• A 15-month-old boy with a negative newborn screen presented with unilateral epithelial defects and palmoplantar hyperkeratosis.
• He later developed bilateral dendritiform epithelial erosions and global developmental delay.
• Diagnosis of Tyrosinemia Type II was confirmed by elevated tyrosine and phenylalanine levels.

Findings:

• The patient's ocular symptoms and epithelial defects resolved after initiating a low-protein diet.
• This case highlights the potential for oculocutaneous tyrosinemia despite negative newborn screening.

Implications:

• Dendritiform epithelial erosions, developmental delay, and palmoplantar hyperkeratosis warrant tyrosine and phenylalanine level measurement.
• Early recognition of ocular signs is vital for timely diagnosis and intervention.
• Prompt dietary modification is essential to prevent irreversible developmental delay in Tyrosinemia Type II.