BDNF and Down syndrome: Fig 2A shows that BDNF level is statistically significatively higher than control subjects of the same age range (children Down's syndrome patients 36.94 ± 22.15 SD pg/mL, children control 7.178 ± 0.468, p < 0.05; adult Down's syndrome patients 44.98 ± 21.34 SD pg/mL, adult control 8.14 ± 1.274 SD pg/mL, p < 0.001; old Down's syndrome patients 69.83 ± 22.15 SD pg/mL, old control 11.245 ± 1.035 SD pg/mL, p < 0.001).