Normal Outcome With Prenatal Intervention for Riboflavin Transporter Defect.

BACKGROUND:Riboflavin transporter deficiency is a rare but severe neurometabolic disorder. METHODS:We report two siblings with pathogenic variants in SLC52A3 gene, resulting in riboflavin transporter 3 deficiency. RESULTS:The first sibling was diagnosed at age 11 months with severe respiratory compromise and regression of developmental milestones. His symptoms significantly improved with riboflavin supplementation therapy. The younger sibling was diagnosed by antenatal genetic analysis; riboflavin supplementation was initiated in utero and continued from birth. Now at age two years, he remains clinically asymptomatic despite genetic confirmation of riboflavin transporter deficiency. CONCLUSIONS:Antenatal riboflavin supplementation is a safe and effective treatment for the prevention of symptomatic manifestations of riboflavin transporter deficiency.