High-affinity transporter for the intake of thiamine (PubMed:10391222, PubMed:10542220, PubMed:21836059, PubMed:33008889, PubMed:35512554, PubMed:35724964). Mediates H(+)-dependent pyridoxine transport (PubMed:33008889, PubMed:35512554, PubMed:35724964)

Cell membrane

Thiamine-responsive megaloblastic anemia syndrome

An autosomal recessive disease characterized by megaloblastic anemia, diabetes mellitus, and sensorineural deafness. Onset is typically between infancy and adolescence, but all of the cardinal findings are often not present initially. The anemia, and sometimes the diabetes, improves with high doses of thiamine. Other more variable features include optic atrophy, congenital heart defects, short stature, and stroke.

Bifunctional enzyme catalyzing the last two steps of de novo pyrimidine biosynthesis, orotate phosphoribosyltransferase (OPRT), which converts orotate to orotidine-5'-monophosphate (OMP), and orotidine-5'-monophosphate decarboxylase (ODC), the terminal enzymatic reaction that decarboxylates OMP to uridine monophosphate (UMP)

Orotic aciduria 1

A disorder of pyrimidine metabolism resulting in megaloblastic anemia and orotic acid crystalluria that is frequently associated with some degree of physical and intellectual disability. A minority of cases have additional features, particularly congenital malformations and immune deficiencies.