Bibian van der Voorn

109 GR/MR VARIATION ON IQ & BEHAVIOR AFTER PREMATURITY SNPS OF THE GLUCOCORTICOID AND MINERALOCORTICOID RECEPTORS Two SNPs in the GR , R23K (rs 6190) and N363S (rs 6195), and two in the MR , -2G/C (rs 2070951) and I180V (rs 5522), were analyzed. PCRs were performed using 2.5 ng of genomic DNA and standard reagents. SNPs were genotyped by mass spectrometry (homogeneous mass array system to Sequenom Inc., San Diego, CA), using standard conditions. Genotypes were analyzed, using Genotyper 3.0 software (Sequenom). IQ Intellectual functioning was assessed in 2002 by the digital Multicultural Capacity Test–Intermediate Level, developed and validated by Bleichrodt and Van den Berg in 2000 22 . The test derives an IQ-score, indicating the level of general cognitive performance, together with scores on a wide spectrum of intellectual dimensions, giving a broader perspective on cognitive functioning. Overall, this test represents a person’s capacities and skills: verbal and numerical intelligence, spatial visualization, speech fluency, memory, reasoning, and speed of perception. The test is validated for persons aged ≥ 16 years, from different backgrounds, whose level of education ranges from 5 years of secondary school to university. In the normal Dutch population this test reports an IQ-score of (mean ± SD) 100 ± 15 22 . BEHAVIOR Behavior was assessed by the young adult self-report (YASR) and the young adult behaviorchecklist(YABCL)forparents.Thesequestionnairesarebasedon,respectively 130 and 109 items assessing behavior on a 3-point scale: 0 (not true), 1 (somewhat true) and 2 (often true). Both tests provide syndrome scores (anxious/depressed, withdrawn, somatic complaints, aggressive behavior, delinquent behavior, thought problems, attention problems, intrusive behavior and other problems), total sum- scores as well as internalizing and externalizing sum-scores. Internalizing behavior is calculated as the sum of anxious/depressed and withdrawn behavior. Externalizing behavior is calculated as the sum of aggressive, delinquent, and intrusive behavior 23 . A high score indicates that the person shows more of the related problem behavior. STATISTICAL ANALYSES IQ-scores were normally distributed and presented as mean ± SD. YASR and YABCL scores were skewed to the right, which did not change after logarithmic