Background: Phelan-McDermid syndrome is a genetic disorder caused by haploinsufficiency of the SHANK3 gene on chromosome 22q13.3 and is characterized by autism spectrum disorder, intellectual disability, speech and language abnormalities, hypotonia, and mild dysmorphic features. Early literature in Phelan-McDermid syndrome did not include gait abnormalities as part of the syndrome although recent prospective studies report that the prevalence of gait abnormalities ranges from 55% to 94%. We compared gait abnormalities in individuals with Phelan-McDermid syndrome, idiopathic autism spectrum disorder, and typically developing controls, and explored associations between gait abnormalities, autism spectrum disorder, and intellectual functioning. Method: The study cohort consists of 67 participants between the ages of 3 and 18 years, divided into 3 groups: Phelan-McDermid syndrome (n  =  46), idiopathic autism spectrum disorder (n  =  11), and typically developing controls (n  =  10). Gait was recorded using a video camera and scored across 26 gait features using a "Gait Clinical Observations scale" designed specifically for this study. Results: Gait abnormalities were significantly higher in the Phelan-McDermid syndrome group as compared to idiopathic autism spectrum disorder or typically developing controls. The number of gait abnormalities across groups was also significantly correlated with Intellectual Quotient/Developmental Quotient (IQ/DQ). In analysis of covariance including IQ/DQ, the effect of group was not significant, but the effect of IQ/DQ was significant. Conclusions: Overall differences in gait abnormalities were determined by the degree of intellectual disability, which was significantly higher in Phelan-McDermid syndrome.

中文翻译：

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费兰-麦克德米德综合征儿童的步态异常。

背景：Phelan-McDermid 综合征是一种由染色体 22q13.3 上 SHANK3 基因单倍体不足引起的遗传性疾病，其特征为自闭症谱系障碍、智力障碍、言语和语言异常、张力减退和轻度畸形特征。尽管最近的前瞻性研究报告称步态异常的患病率在 55% 至 94% 之间，但有关 Phelan-McDermid 综合征的早期文献并未将步态异常纳入该综合征的一部分。我们比较了费兰-麦克德米德综合征、特发性自闭症谱系障碍和典型发育对照个体的步态异常，并探讨了步态异常、自闭症谱系障碍和智力功能之间的关联。方法：研究队列由 67 名年龄在 3 至 18 岁之间的参与者组成，分为 3 组：Phelan-McDermid 综合征 (n = 46)、特发性自闭症谱系障碍 (n = 11) 和典型发育对照 (n = 10）。使用摄像机记录步态，并使用专门为本研究设计的“步态临床观察量表”对 26 个步态特征进行评分。结果：与特发性自闭症谱系障碍或典型发育对照组相比，费兰-麦克德米德综合征组的步态异常明显更高。各组步态异常的数量也与智商/发育商数（IQ/DQ）显着相关。在包括IQ/DQ在内的协方差分析中，分组的影响不显着，而IQ/DQ的影响显着。结论：步态异常的总体差异由智力障碍的程度决定，费兰-麦克德米德综合征的智力障碍程度明显较高。