Sex chromosome trisomies (SCT), including Klinefelter syndrome/XXY, Trisomy X, and XYY syndrome, occur in 1 of every 500 births. The past decades of research have resulted in a broadening of known associated medical comorbidities as well as advances in psychological research. This review summarizes what is known about early neurodevelopmental, behavioral, and medical manifestations in young children with SCT. We focus on recent research and unanswered questions related to the risk for neurodevelopmental disorders that commonly present in the first years of life and discuss the medical and endocrine manifestations of SCT at this young age. The increasing rate of prenatal SCT diagnoses provides the opportunity to address gaps in the existing literature in a new birth cohort, leading to development of the eXtraordinarY Babies Study. This study aims to better describe and compare the natural history of SCT conditions, identify predictors of positive and negative outcomes in SCT, evaluate developmental and autism screening measures commonly used in primary care practices for the SCT population, and build a rich data set linked to a bank of biological samples for future study. Results from this study and ongoing international research efforts will inform evidence‐based care and improve health and neurodevelopmental outcomes.

中文翻译：

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性染色体三体性儿童的早期神经发育和医学特征：前瞻性婴儿研究的背景，以识别早期危险因素和干预目标。

每500名婴儿中就有1名发生性染色体三体性（SCT），包括Klinefelter综合征/ XXY，X染色体三体和XYY综合征。过去几十年的研究导致已知的相关医学合并症的扩大以及心理学研究的发展。这篇综述总结了关于SCT幼儿早期神经发育，行为和医学表现的已知知识。我们专注于与生命发育初期常见的神经发育障碍风险相关的最新研究和未解决的问题，并讨论了这个年轻年龄段SCT的医学和内分泌表现。产前SCT诊断率的提高为解决新出生队列中现有文献中的空白提供了机会，从而促进了超婴儿研究的发展。这项研究旨在更好地描述和比较SCT病情的自然史，确定SCT阳性和阴性结果的预测因素，评估SCT人群初级保健实践中常用的发育和自闭症筛查措施，并建立与SCT人群相关的丰富数据集。一组生物样本以备将来研究。这项研究和正在进行的国际研究的结果将为循证护理提供信息，并改善健康和神经发育结局。