Quantitative abnormalities of A/J-trac/trac mice. (A) Survival data showing the short life span of A/J-trac/trac mice. There was no significant difference in life span of males and females (n = 18). (B-C) Platelet numbers and platelet volumes in A/J-trac/trac and +/? sex-matched littermate mice. Each bar represents the mean and SE from 4 to 9 mice analyzed at 10 to 17 weeks of age. (B) Platelet numbers showing severely reduced counts in A/J-trac/trac mice. (C) Platelet volumes showing markedly increased volumes in A/J-trac/trac mice. (D) Bleeding times were prolonged in A/J-trac/trac mice; n = 5 pairs of 6- to 12-week-old A/J-trac/trac and control mice. (E) Platelet activation was impaired in A/J-trac/trac mice at 3 to 4 weeks of age (n = 4). (F) In 3-week-old A/J-trac/trac mice, platelet aggregation was not significantly different from controls, but by 11 weeks of age they had greatly reduced platelet aggregation performance as measured by the whole blood impedance method. Data show area under the curve using the whole blood impedance method. (G) RBC fragility graph showing increased fragility of A/J-trac/trac RBCs (*P < .05; **P < .01; ***P < .001).