目的　探讨Smith-Magenis综合征（SMS）的临床特点。方法　回顾分析1例SMS患儿的临床资料及分子遗传 学检测结果，并复习相关文献。结果　患儿，男， 5岁9个月，因动作智力发育落后就诊。患儿自幼入睡困难，易醒，动作多， 有撞头、抓伤皮肤、拔甲等自我伤害行为；面容特殊，发际低、前额宽阔、面部平、低鼻梁、上唇外翻、牙釉质发育不良，手 指短，手短而宽。头部磁共振成像示脑室扩大，透明隔间腔增宽。染色体微阵列分析显示17p11.2存在缺失，缺失长度为3.07 Mb，分子核型为46，XY. Arr 17p11.2 （17,143,150-20,213,815）× 1，确诊为SMS。结论　SMS主要表现为智力运动发 育迟缓、特殊面容、睡眠障碍、行为异常等，染色体微阵列分析有助于早期诊断。

Objective　To explore the clinical characteristics of Smith-Magenis syndrome (SMS). Methods　The clinical data and the results of molecular genetics detection of SMS in a child were retrospectively analyzed and the related literature was reviewed. Results　A boy, aged 5 years and 9 months, suffered from psychomotor retardation. He had sleep disorders since childhood including trouble falling asleep and shortened sleep cycles. He also had neurobehavioral symptoms including hyperactivity and self-injurious behaviors including bumping head, scratching and yanking fingernails. The patient had special facial features such as low hairline, broad forehead, flat face, low nasal bridge, tented upper lip and enamel dysplasia, brachydactyly, short and broad hands. Head magnetic resonance imaging showed enlargement of cerebral ventricle and cavum septum pellucidum. Chromosome microarray analysis showed a deletion of 17p11.2 with a length of 3.07 Mb [arr 17p11.2 (17,143,150-20,213,815) ×1]. The molecular karyotype was ascertained as 46, XY and Smith-Magenis syndrome was diagnosed finally. Conclusions　For children with psychomotor retardation, distinct facial phenotype, sleep disorders, behavioral disorders, Smith-Magenis syndrome should be considered. Chromosomal microarry analysis contributes to the early diagnosis of SmithMagenis syndrome.