Moderating effect of mode of delivery on the genetics of intelligence: Explorative genome‐wide analyses in ALSPAC

Abstract

IntroductionIntelligence is a core construct of individual differences in cognitive abilities and a strong predictor of important life outcomes. Within recent years, rates of cesarean section have substantially increased globally, though little is known about its effect on neurodevelopmental trajectories. Thus, we aimed to investigate the influence of delivery by cesarean section on the genetics of intelligence in children.MethodsParticipants were recruited through the Avon Longitudinal Study of Parents and Children (ALSPAC). Intelligence was measured by the Wechsler Intelligence Scale for Children (WISC). Genotyping was performed using the Illumina Human Hap 550 quad genome‐wide SNP genotyping platform and was followed by imputation using MACH software. Genome‐wide interaction analyses were conducted using linear regression.ResultsA total of 2,421 children and 2,141,747 SNPs were subjected to the genome‐wide interaction analyses. No variant reached genome‐wide significance. The strongest interaction was observed at rs17800861 in the GRIN2A gene (β = −3.43, 95% CI = −4.74 to −2.12, p = 2.98E−07). This variant is predicted to be located within active chromatin compartments in the hippocampus and may influence binding of the NF‐kappaB transcription factor.ConclusionsOur results may indicate that mode of delivery might have a moderating effect on genetic disposition of intelligence in children. Studies of considerable sizes (>10,000) are likely required to more robustly detect variants governing such interaction. In summary, the presented findings prompt the need for further studies aimed at increasing our understanding of effects various modes of delivery may have on health outcomes in children.

Cognitive Skills, Strategic Sophistication, and Life Outcomes

“…As we note in Section 2, fluid intelligence is the ability to use logical reasoning to solve new problems, while crystallized intelligence includes acquired knowledge and verbal skills (e.g., Carpenter et al, 1990). WISC-III captures both fluid intelligence (Dickson et al, 2016) and crystallized intelligence (Smajlagić et al, 2018). The WISC-III Full Scale IQ score is based on ten subtests: information; similarities; arithmetic; vocabulary; comprehension; picture completion; coding; picture arrangement; block design; and object assembly.…”

Children’s Greenness Exposure and IQ-Associated DNA Methylation: A Prospective Cohort Study

“…A total of 400 CpG sites were selected from 6 EWAS [ 26 , 45 , 46 , 47 , 48 , 49 ]. Additionally, a total of 31,981 CpG sites were selected, which were annotated to 835 genes reported from 13 GWAS after excluding duplicate genes [ 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 ]. As a result, 8743 CpG sites were finally selected ( Tables S2 and S3 ).…”

Influence of Mode of Delivery on Children’s Attention Deficit Hyperactivity Disorder and Childhood Intelligence

“…Curran et al [ 31 ] assessed the school performance in Swedish adolescents with 1,036,424 children born by unassisted vaginal delivery and 42,107 by elective cesarean section and found poor school performance was observed more in adolescents with cesarean-section birth. The method of delivery may moderate the genetic disposition (rs705670 on chromosome 9) of PIQ in children [ 16 ]. The rs705670 on chromosome 9 for PIQ, LINC01502 , have recently been implicated in several neuropsychiatric disorders where IQ is affected, such as ADHD [ 32 ].…”

“…However, other research showed no association between cesarean deliveries with better cognitive development in children [ 15 ]. A recent study revealed that mode of delivery can moderate the genetics of intelligence based on an explorative genome-wide analysis [ 16 ]. There is an urgent need for further studies that may increase our understanding of effects of delivery modes on intelligence in children.…”