Riboflavin Transporter Deficiency as a Cause of Progressive Encephalopathy.

Area of Science:

• Genetics and Neurology
• Rare Diseases
• Metabolic Disorders

Background:

• Riboflavin transporter deficiency (RTD) is a rare neurodegenerative disease previously classified as Brown-Vialetto-Van Laere or Fazio-Londe syndrome.
• RTD2, specifically, results from mutations in the SLC52A2 gene, leading to symptoms like encephalopathy, neuropathy, hearing loss, and respiratory issues.
• Riboflavin (vitamin B2) is crucial for producing flavin cofactors (FMN, FAD), essential for numerous metabolic and cellular processes.

Purpose of the Study:

• To describe two pediatric cases of RTD2 caused by SLC52A2 mutations.
• To report the successful inhibition of disease progression using vitamin B2 supplementation in these patients.
• To discuss the clinical presentation and findings in the context of existing RTD2 literature.

Main Methods:

• Case study of two siblings diagnosed with RTD2.
• Genetic analysis confirmed mutations in the SLC52A2 gene (c.916G>C and c.477C>G).
• Treatment involved vitamin B2 supplementation at varying doses, with monitoring of disease progression.

Main Results:

• Both patients presented with psychomotor developmental delay, ataxia, nystagmus, hearing loss, and lack of visual fixation.
• Vitamin B2 supplementation successfully inhibited the progression of the disease in both children.
• The observed phenotype aligns with previously reported cases of RTD2.

Conclusions:

• Vitamin B2 supplementation is an effective treatment for RTD2 caused by SLC52A2 mutations.
• Early diagnosis and intervention with vitamin B2 can halt disease progression in RTD2 patients.
• This study contributes to understanding the clinical spectrum and therapeutic options for RTD2.