Riboflavin and CoQ Disorders

Riboflavin, or vitamin B2, is the precursor of flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), which are essential cofactors of numerous dehydrogenases. The most common form of riboflavin disorder is its deficiency due to insufficient dietary intake. Riboflavin-responsive inborn errors of metabolism were shown to be due to the riboflavin chaperone-like function, which stabilises mutant FAD-containing dehydrogenases, most often ETFDH. Recessive mutations of SLC52A2 and SLC52A3 encoding the human riboflavin transporters RFVT2 and RFVT3 are cause Brown-Vialetto-Van Laere and Fazio-Londe syndromes, while haploinsufficiency of SLC52A1 has been proposed to cause persistent riboflavin deficiency.