BACKGROUND Neurodevelopmental disorders such as 16p11.2 syndrome are frequently associated with motor impairments including locomotion. The lack of precise measures of gait, combined with the challenges inherent in studying children with neurodevelopmental disorders, hinders quantitative motor assessments. Gait and balance are quantifiable measures that may help to refine the motor phenotype in 16p11.2. The characterization of motor profile is useful to study the trajectories of locomotion performance of children with genetic variants and may provide insights into neural pathway dysfunction based on genotype/phenotype model. METHODS Thirty-six children (21 probands with 16p11.2 deletion and duplication mutation and 15 unaffected siblings), with a mean age of 8.5 years (range 3.2-15.4) and 55% male, were enrolled. Of the probands, 23% (n = 6) had a confirmed diagnosis of autism spectrum disorder (ASD) and were all male. Gait assessments included 6-min walk test (6MWT), 10-m walk/run test (10MWR), timed-up-and-go test (TUG), and spatio-temporal measurements of preferred- and fast-paced walking. The Pediatric Evaluation of Disability Inventory-Computer Adaptive Tests (PEDI-CAT), a caregiver-reported functional assessment, was administered. Measures of balance were calculated using percent time in double support and base of support. Analyses of the six children with ASD were described separately. RESULTS Thirty-six participants completed the protocol. Compared with sibling controls, probands had significantly lower scores on the 6MWT (p = 0.04), 10MWR (p = 0.01), and TUG (p = 0.005). Group differences were also identified in base of support (p = 0.003). Probands had significantly lower PEDI-CAT scores in all domains including the mobility scale (p < 0.001). Using age-matched subsamples, the ASD and non-ASD genetic variant groups had larger base of support compared to the controls. In the fast-paced condition, all participants increased their velocity, and there was a corresponding decrease in percent time in double support compared to the preferred-pace condition in all participants. Only the ASD group presented with upper limb arm/hand stereotypies. CONCLUSIONS Children with 16p11.2, with and without ASD, present with balance impairment during locomotion activities. Probands performed worse on functional assessments, and quantitative measures revealed differences in base of support. These results highlight the importance of using precise measures to differentiate motor dysfunction in children with neurodevelopmental disorders.

中文翻译：

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16p11.2综合征儿童的定量步态评估。

背景技术诸如16p11.2综合征的神经发育障碍通常与包括运动的运动障碍有关。缺乏精确的步态测量方法，再加上研究儿童神经发育障碍所固有的挑战，阻碍了定量运动评估。步态和平衡是可量化的措施，可能有助于改善16p11.2中的运动表型。运动特征的表征对于研究具有遗传变异的儿童的运动表现轨迹是有用的，并且可以提供基于基因型/表型模型的神经通路功能障碍的见解。方法招募了36名儿童（21名先证者，具有16p11.2缺失和重复突变，以及15名未受影响的兄弟姐妹），平均年龄为8.5岁（范围3.2-15.4），男性为55％。在先证者中，23％（n = 6）的患者被诊断出患有自闭症谱系障碍（ASD），并且均为男性。步态评估包括6分钟步行测试（6MWT），10米步行/跑步测试（10MWR），定时走步测试（TUG）以及时空测量的首选和快节奏步行。护理人员报告的功能评估是儿科残疾评估计算机适应性测试（PEDI-CAT）。平衡的度量是使用双重支持和支持基础中的时间百分比来计算的。分别描述了六个患自闭症儿童的分析。结果三十六名参与者完成了实验方案。与同级对照相比，先证者在6MWT（p = 0.04），10MWR（p = 0.01）和TUG（p = 0.005）上的得分明显较低。在支持基础上也确定了组差异（p = 0.003）。先证者在所有领域中的PEDI-CAT得分均显着降低，包括迁移率量表（p <0.001）。与对照相比，使用年龄匹配的子样本，ASD和非ASD基因变异组具有更大的支持基础。在快节奏条件下，与所有参与者中的首选步伐条件相比，所有参与者都提高了自己的速度，并且双支撑的百分比时间也相应减少了。仅ASD组出现上肢手臂/手的定型观念。结论16p11.2患儿，无论是否患有ASD，在运动过程中都会出现平衡障碍。先证者在功能评估中的表现较差，定量方法显示支持基础不同。