Table 3. APP mRNA expression in blood.

	n	Mean	SEMa	Median	Range
Controlsb	58	1.01	0.02	0.99	0.68–1.46
Down syndrome	21	1.46	0.07	1.49	0.80–2.05
APP duplication	12	1.40	0.10	1.39	0.79–1.89
Patient with c.*331_*332del	1	1.47±0.06c
Unaffected mother, not carrying the c.*331_332 del mutation	1	1.12±0.06c

Relative APP mRNA levels in 58 control individuals, 21 patients with Down syndrome, 12 patients with APP duplication[6], and the patient carrying the c.*331_*332del mutation in the APP 3'UTR. Each individual value corresponds to the average of three measures by RT-QMPSF.

^aStandard error of mean among the 58 controls, the 21 patients with Down syndrome, and the 12 patients with APP duplication, respectively, as a reflect of inter-individual variation.

^bMean age±SEM: 64.6±1.16.

^cStandard error of mean of the three analysis replicates of RT-QMPSF in the patient carrying the c.*331_*332del mutation and his unaffected mother, respectively, as a reflect of measure variability.