[A case of fundus albipunctatus with a retinol dehydrogenase 5 gene mutation in a child].

Area of Science:

• Ophthalmology
• Medical Genetics
• Molecular Biology

Background:

• Fundus albipunctatus is an inherited retinal disorder characterized by multiple white spots in the fundus.
• The genetic basis of fundus albipunctatus is not fully understood, with mutations in the RDH5 gene being a suspected cause.

Observation:

• An 8-year-old girl presented with diffuse white dots in her fundus, normal central vision, reduced electroretinogram amplitude, and impaired dark adaptation.
• Clinical examination revealed no visual field loss.
• Genetic analysis identified a homozygous missense mutation (Arg280His) in exon 5 of the RDH5 gene in the affected girl.

Findings:

• A novel homozygous missense mutation, RDH5 Arg280His, was identified as the cause of fundus albipunctatus in this family.
• The patient's mother was heterozygous for the same mutation, indicating an autosomal recessive inheritance pattern.
• The mutation affects a critical region of the RDH5 protein, likely impacting its enzymatic function in vitamin A metabolism.

Implications:

• This finding confirms the role of RDH5 gene mutations in fundus albipunctatus.
• Understanding the specific mutation provides insights into the molecular mechanisms underlying the disease.
• Genetic diagnosis of RDH5 mutations can aid in family counseling and potential future therapeutic strategies for inherited retinal dystrophies.