However, we observed age‐ and stress‐related alterations in three behavioral traits in Mrps5 V338Y mutant mice: first, increased anxiety responses as evidenced by less time spent in the center of the open field and more time spent in the dark chamber of the light–dark transition test; second, decreased explorative drive as revealed by diminished vertical activity and a smaller area explored in the open field; and third, impaired learning and memory under stressful conditions as shown by poor training and probe trial scores in the water‐maze place navigation tests. This evidence concerns the gene MRPS5 and Anxiety.