Different Clinic, Different Diagnosis: Tyrosinemia Type 3

Area of Science:

• Genetics
• Metabolic Disorders
• Ophthalmology

Background:

• Tyrosinemia type III is a rare autosomal recessive metabolic disorder caused by HPD gene mutations.
• Clinical manifestations are not fully understood, with neurodevelopmental issues being common and ocular involvement rare.
• Limited cases reported globally hinder understanding of the full disease spectrum.

Purpose of the Study:

• To report a case of Tyrosinemia type III with atypical ocular presentation.
• To highlight the importance of considering metabolic disorders in infants with severe photosensitivity.
• To emphasize the need for long-term monitoring of potential complications.

Main Methods:

• Presented a case of a 9-month-old girl with severe photophobia and allergic conjunctivitis.
• Conducted biochemical and genetic investigations to identify HPD gene variants.
• Implemented a phenylalanine- and tyrosine-restricted diet.

Main Results:

• Diagnosed Tyrosinemia type III based on two novel heterozygous HPD gene variants.
• Observed significant reduction in plasma tyrosine levels post-dietary intervention.
• Noted improvement in the patient's clinical symptoms, including ocular issues.

Conclusions:

• Infants with severe photosensitivity and conjunctivitis may have underlying inherited metabolic disorders.
• Early diagnosis and dietary management of Tyrosinemia type III can improve outcomes.
• Long-term follow-up is crucial for managing potential neurological and ocular complications.