BACKGROUND Younger siblings of children with autism spectrum disorder (ASD) are at increased likelihood of receiving an ASD diagnosis and exhibiting other developmental concerns. It is unknown how quantitative variation in ASD traits and broader developmental domains in older siblings with ASD (probands) may inform outcomes in their younger siblings. METHODS Participants included 385 pairs of toddler siblings and probands from the Infant Brain Imaging Study. ASD probands (mean age 5.5 years, range 1.7 to 15.5 years) were phenotyped using the Autism Diagnostic Interview-Revised (ADI-R), the Social Communication Questionnaire (SCQ), and the Vineland Adaptive Behavior Scales, Second Edition (VABS-II). Siblings were assessed using the ADI-R, VABS-II, Mullen Scales of Early Learning (MSEL), and Autism Diagnostic Observation Schedule (ADOS) and received a clinical best estimate diagnosis at 24 months using DSM-IV-TR criteria (n = 89 concordant for ASD; n = 296 discordant). We addressed two aims: (1) to determine whether proband characteristics are predictive of recurrence in siblings and (2) to assess associations between proband traits and sibling dimensional outcomes at 24 months. RESULTS Regarding recurrence risk, proband SCQ scores were found to significantly predict sibling 24-month diagnostic outcome (OR for a 1-point increase in SCQ = 1.06; 95% CI = 1.01, 1.12). Regarding quantitative trait associations, we found no significant correlations in ASD traits among proband-sibling pairs. However, quantitative variation in proband adaptive behavior, communication, and expressive and receptive language was significantly associated with sibling outcomes in the same domains; proband scores explained 9-18% of the variation in cognition and behavior in siblings with ASD. Receptive language was particularly strongly associated in concordant pairs (ICC = 0.50, p < 0.001). CONCLUSIONS Proband ASD symptomology, indexed by the SCQ, is a predictor of familial ASD recurrence risk. While quantitative variation in social communication and restricted and repetitive behavior were not associated among sibling pairs, standardized ratings of proband language and communication explained significant variation in the same domains in the sibling at 24 months, especially among toddlers with an ASD diagnosis. These data suggest that proband characteristics can alert clinicians to areas of developmental concern for young children with familial risk for ASD.

中文翻译：

---

24个月时ASD先证者的数量性状变异和学步的兄弟姐妹结局。

背景技术患有自闭症谱系障碍（ASD）的儿童的年轻同胞越来越有可能接受ASD诊断并表现出其他发展问题。尚不清楚ASD（先证者）老年兄弟姐妹的ASD性状和较宽的发育范围的定量变化如何影响其年轻兄弟姐妹的结局。方法参与者包括385对来自婴儿脑成像研究的学步兄弟姐妹和先证者。使用自闭症诊断访谈修订版（ADI-R），社会沟通问卷（SCQ）和Vineland适应行为量表第二版（VABS-II）对ASD先证者（平均年龄5.5岁，范围1.7至15.5岁）进行表型分析。 ）。使用ADI-R，VABS-II，穆伦早期学习量表（MSEL）对兄弟姐妹进行评估，和自闭症诊断观察时间表（ADOS），并使用DSM-IV-TR标准在24个月时收到临床最佳估计诊断（n = 89与ASD一致； n = 296与不一致）。我们实现了两个目标：（1）确定先证者特征是否可预测兄弟姐妹的复发；（2）评估24个月时先证者特征与兄弟姐妹维度结果之间的关联。结果关于复发风险，先证者SCQ得分可显着预测同胞24个月的诊断结果（OR为SCQ上升1分= 1.06； 95％CI = 1.01、1.12）。关于数量性状关联，我们发现先证-同胞对之间的ASD性状没有显着相关性。但是，先证者适应行为，沟通，在同一个领域，表达性和接受性语言与同胞结局显着相关；先证者分数解释了ASD兄弟姐妹认知和行为变异的9-18％。接受语言在一致对中尤其紧密相关（ICC = 0.50，p <0.001）。结论由SCQ索引的Proband ASD症状是家族性ASD复发风险的预测指标。虽然同胞对之间没有社会交往的定量变化以及受限和重复的行为，但先证者语言和交际的标准化评级解释了同胞在同一个领域在24个月时的显着变化，特别是在患有ASD诊断的幼儿中。