RNA microarray analysis of channels and transporters in normal and fetal Down syndrome (trisomy 21) brain

A couple of transporters and channels has been proposed as candidate genes involved in the pathomechanisms leading to the neurodevelopmental abnormalities and the phenotype of Down Syndrome (DS, trisomy 21). No systematic study, however, has been carried out showing the concomitant expression of several candidate RNAs during fetal life. It was therefore the aim of the study to apply an array of 96 brain RNAs mainly consisting of channels and transporters to show their expressional levels in fetal DS brain at the early second trimester. Brain RNA was extracted from fetal cortex of the 18-19th week of gestation of controls and DS individuals and used for the GEArray Q Series Human Neuroscience-1/Ion Channels & Transporters analysis. 15 out of 96 RNAs of the array were observed on the films in both groups during this gestational period consisting of genes for potassium, sodium, calcium channels and transporters (ASIC3, ATP1B1, CACNA1B, KCNB2, KCNC1, KCND2, KCNF1, KCNN1, KCNN3, hKCa4, KCNQ2, lipid transfer protein II, SCN2B, acetyl choline transporter, glutamate transporter3). There was no statistically significant difference between the control and the DS group. We provide information on the developmental expression of the aforementioned 15 RNAs and the absence of the residual examined 81 RNAs at the 18th/19th week of gestation in fetal cortex that was never reported before and show that channels and transporters present with unchanged expression in fetal DS brain.