Smith‒Magenis syndrome (SMS, OMIM: 182290) is a multiple congenital anomalies and intellectual disability syndrome due to a 3.45 Mb microdeletion involving 17p11.2 and is estimated to occur about one in 25,000 births. Up to now, the ultrasound findings of the foetus with SMS and their external genital defects in patients are rarely reported. This case indicates that foetus with SMS may present polyhydramnios and ventriculomegaly in the second trimester. The newborn male patient had an abnormal phenotype in which he has micropenis and his anus is close to the perineal body. The identification of this case may further expand the phenotypic spectrum of this genetic disorder.

中文翻译：

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与 Smith-Magenis 综合征和外生殖器缺陷相关的 17p11.2p12 从头微缺失的产前诊断和新生儿表型

Smith-Magenis 综合征 (SMS, OMIM: 182290) 是一种多发性先天性异常和智力障碍综合征，由 17p11.2 的 3.45 Mb 微缺失引起，估计每 25,000 个新生儿中就有一个发生。目前，SMS胎儿及其外生殖器缺陷的超声表现鲜见报道。该病例表明，患有 SMS 的胎儿可能在孕中期出现羊水过多和脑室扩大。新生男性患者有一个异常的表型，他有小阴茎，肛门靠近会阴体。该病例的鉴定可能会进一步扩大这种遗传疾病的表型谱。