Department of Psychology and Neuroscience, Duke University, Durham, NC, USA.
Frank Porter Graham Child Development Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
J Child Psychol Psychiatry. 2020 Dec;61(12):1349-1359. doi: 10.1111/jcpp.13224. Epub 2020 Mar 27.
A recent genome-wide association study identified molecular-genetic associations with age-at-first-birth. However, the meaning of these genetic discoveries is unclear. Drawing on evidence linking early pregnancy with disinhibitory behavior, we tested the hypothesis that genetic discoveries for age-at-first-birth predict disinhibition.
We included participants with genotype data from the two-decade-long Environmental Risk (E-Risk) Study (N = 1,999) and the four-decade-long Dunedin Study (N = 918). We calculated a genome-wide polygenic score for age-at-first-birth and tested whether it was associated with a range of disinhibitory outcomes across the life course, including low childhood self-control; risk for externalizing psychopathology; officially recorded criminal offending; substance dependence; informant reports of disinhibitory problems; and number of lifetime sexual partners. We further tested whether associations were attributable to accelerated pubertal maturation.
In both cohorts, the age-at-first-birth polygenic score predicted low childhood self-control, externalizing psychopathology, officially recorded criminal offending, substance dependence, and number of sexual partners. Associations were modest, but robust across replication. Childhood disinhibition partly mediated associations between the polygenic score and reproductive behaviors. In contrast, associations were not attributable to accelerated pubertal timing.
Genomic discoveries for age-at-first-birth are about more than reproductive biology: They provide insight into the disinhibitory traits and behaviors that accompany early parenthood. Age-at-first-birth is a useful proxy phenotype for researchers interested in disinhibition. Further, interventions that improve self-regulation abilities may benefit young parents and their children.
最近的全基因组关联研究确定了与首次生育年龄相关的分子遗传关联。然而，这些遗传发现的意义尚不清楚。基于早期妊娠与去抑制行为相关的证据，我们检验了这样一个假设，即首次生育年龄的遗传发现可以预测去抑制。
我们纳入了来自长达 20 年的环境风险（E-Risk）研究（N=1999）和长达 40 年的达尼丁研究（N=918）的具有基因型数据的参与者。我们计算了一个用于首次生育年龄的全基因组多基因评分，并检验了它是否与一生中一系列去抑制的结果有关，包括童年期自我控制水平低；外化型精神病理学风险；官方记录的犯罪行为；物质依赖；去抑制问题的知情者报告；以及终生性伴侣的数量。我们进一步检验了这些关联是否归因于青春期成熟的加速。
在两个队列中，首次生育年龄的多基因评分预测了童年期自我控制水平低、外化型精神病理学、官方记录的犯罪行为、物质依赖和性伴侣数量。这些关联虽然不大，但在复制中是稳健的。童年期去抑制在多基因评分与生殖行为之间的关联中起部分中介作用。相比之下，这些关联与青春期加速无关。
首次生育年龄的基因组发现不仅仅与生殖生物学有关：它们为伴随早期为人父母而来的去抑制特征和行为提供了深入的了解。首次生育年龄是对去抑制感兴趣的研究人员的一个有用的替代表型。此外，提高自我调节能力的干预措施可能有益于年轻的父母及其子女。
