Deletion of one allele of Mthfd1 (methylenetetrahydrofolate dehydrogenase 1) impairs learning in mice

•We evaluated whether behavioral abnormalities occur with loss of one allele of Mthfd1 via a gene-trap mutation.•Mthfd1gt/+ mice display impaired learning.•These data provide an extensive behavioral profile of both male and female Mthfd1gt/+ mice.