Pediatric traumatic brain injury (TBI) can lead to adverse emotional, social, and behavioral consequences. However, outcome is difficult to predict due to significant individual variability, likely reflecting a complex interaction between injury- and child-related variables. Among these variables are genetically determined individual differences, which can modulate TBI outcome through their influence on neuroplasticity mechanisms. In this study, we examined the effect of Val66Met, a common polymorphism of the brain-derived neurotrophic factor gene known to be involved in neuroplasticity mechanisms, on behavioral symptoms of mild TBI (mTBI) sustained in early childhood. This work is part of a prospective, longitudinal cohort study of early TBI. The current sample consisted of 145 children between ages 18 and 60 months assigned to one of three participant groups: mild TBI, orthopedic injury, or typically developing children. Participants provided a saliva sample to detect the presence of the Val66Met polymorphism, and the Child Behavior Checklist was used to document the presence of behavioral symptoms at 6- and 18-months post-injury. Contrary to our initial hypothesis, at 6 months post-injury, non-carriers of the Val66Met polymorphism in the mTBI group presented significantly more internalizing symptoms (e.g., anxiety/depression and somatic complaints) than Val66Met carriers, who were similar to orthopedically injured and typically developing children. However, at 18 months post-injury, all children with mTBI presented more internalizing symptoms, independent of genotype. The results of the study provide evidence for a protective effect of the Val66Met polymorphism on internalizing behavior symptoms 6 months after early childhood mTBI.

中文翻译：

---

早期轻度创伤性脑损伤后脑源性神经营养因子 Val66Met 多态性和内化行为。

小儿创伤性脑损伤 (TBI) 可导致不良的情绪、社交和行为后果。然而，由于显着的个体差异，结果很难预测，这可能反映了伤害和儿童相关变量之间复杂的相互作用。在这些变量中，有基因决定的个体差异，它们可以通过对神经可塑性机制的影响来调节 TBI 结果。在这项研究中，我们检查了 Val66Met（一种已知参与神经可塑性机制的脑源性神经营养因子基因的常见多态性）对儿童早期持续的轻度 TBI (mTBI) 行为症状的影响。这项工作是早期 TBI 前瞻性纵向队列研究的一部分。当前样本包括 145 名年龄在 18 至 60 个月之间的儿童，他们被分配到三个参与者组之一：轻度 TBI、骨科损伤或正常发育的儿童。参与者提供了唾液样本来检测 Val66Met 多态性的存在，并使用儿童行为清单来记录受伤后 6 个月和 18 个月的行为症状的存在。与我们最初的假设相反，在受伤后 6 个月时，mTBI 组中 Val66Met 多态性的非携带者比 Val66Met 携带者表现出明显更多的内化症状（例如，焦虑/抑郁和躯体不适），后者类似于骨科损伤和通常是发育中的儿童。然而，在受伤后 18 个月，所有 mTBI 儿童都表现出更多的内化症状，与基因型无关。