Blood CADPS2ΔExon3 expression is associated with intelligence and memory in healthy adults

Ca(2+)-dependent activator protein for secretion 2 (CADPS2), a secretory granule associate protein, mediates monoamine transmission and neurotrophin release. Both monoamines and neurotrophins play a crucial role in cognition, learning and memory. An aberrant splice variant of CADPS2, CADPS2ΔExon3, was reported to be associated with autism. Therefore, we examined the possible association between the expression of CADPS2/CADPS2ΔExon3 in peripheral blood and brain functions such as intelligence and memory. Quantitative polymerase chain reaction analysis was performed in 271 healthy adults (age range 20-74 years, mean ± SD 43.3 ± 15.3). Data on intelligence quotient (IQ) and memory were obtained by using full versions of the Wechsler Adult Intelligence Scale-Revised (WAIS-R), and the Wechsler Memory Scale-Revised (WMS-R), respectively. CADPS2 expression levels were not significantly associated with any scores/sub-scores of these scales. However, CADPS2ΔExon3 expression was significantly associated with lower IQ (p=0.022; effect size: η(p)(2)=0.031), particularly verbal IQ of WAIS-R (p=0.019; η(p)(2)=0.032), lower verbal memory (p=0.026; η(p)(2)=0.026) and delayed recall (p=0.042; η(p)(2)=0.021) of WMS-R. Our results suggest that CADPS2ΔExon3 affects intelligence and memory in the non-clinical population.