Résumé
We reported two fetal cases diagnosed with Smith-Magenis syndrome.One case was found with bilateral ventriculomegaly,double-outlet right ventricle,pulmonary stenosis and ventricular septal defect when performing fetal echocardiography.Then the fetus was diagnosed with severe tetralogy of Fallot and tortuous ductus arteriosus by autopsy.The other case was suggested to have tetralogy of Fallot,right aortic arch and ectopic ductus arteriosus by fetal echocardiography,which was later confirmed by autopsy.Both of the two pregnancies were terminated.Tissue samples of the two fetuses were analyzed by the low-coverage whole-genome sequencing,and both cases carried a microdeletion of 3.63 Mb and 4.86 Mb in chromosome 17pl 1.2,which overlapped with the missing segments causing Smith-Magenis syndrome.Therefore,the two fetuses were both diagnosed with Smith-Magenis syndrome.