_:vb50939291 . _:vb50939291 . _:vb50939291 "url:https://www.ncbi.nlm.nih.gov/pubmed/1975493"^^ . _:vb50939291 "url:https://www.ncbi.nlm.nih.gov/pubmed/1977311"^^ . _:vb50939291 . _:vb50939291 . _:vb50939291 . _:vb50939291 "A methylmalonic acidemia characterized by accumulation of methylmalonic acid in the blood that is unresponsive to vitamn B12 therapy and that has_material_basis_in mutation in the MUT gene on chromosome 6p12.3."^^ .