A variance homogeneity test of the percentage of lymphocyte subsets with CD3+, CD3 + CD4+/CD3 + CD8+, and CD3–CD19 + cells in children among the IM, P-MI, and HSP groups was carried out, and the results showed that the difference in variance was statistically significant (P < 0.05). The gene discussed is CD4; the disease is hereditary spastic paraplegia.