The response to pyridoxine deprivation and supplementation in control XLSA, XLPP, and EPP male mice. Male mice with the designated genotypes were weaned at age 3 weeks onto a synthetic diet containing defined amounts of pyridoxine. (A) Body weight at age 11 weeks (8 weeks on diet) demonstrating growth retardation in animals of most genotypes on a 0-ppm pyridoxine diet. (B) Selected RBC indices of mice of different genotypes fed defined pyridoxine diets for 8 weeks. (C) Spleen-to-body mass ratio of mice of different genotypes fed 0-ppm pyridoxine diet for 8 weeks. (D) Representative spleens of control and p.R411H mice fed a diet with 0 ppm for 8 weeks. (E) RBC mf-PPIX measured by MFI of control, XLPP, and EPP mice fed defined pyridoxine diets for 8 weeks. n = 5 to 7 mutants and n = 9 to 12 control animals per diet. The dotted line in each panel indicates the average value in control animals. ∗P < .05; ∗∗P < .01; ∗∗∗P < .001; ∗∗∗∗P < .0001, compared with control animals at the same time point. ^#P < .05; ^##P < .01; ^###P < .001; ^####P < .0001, compared with animals of the same genotype on the 10-ppm pyridoxine control diet. B6, pyridoxine; CTL, control; MCV, mean corpuscular volume.