Abstract: 　Objective　To explore the clinical and genetic characteristics of M?bius syndrome in neonates. Methods　The clinical data of a neonate with unilateral M?bius syndrome was retrospectively analyzed, and the relevant literature was reviewed. Results　A female neonate manifested with paralysis of the left facial nerve and abducens nerve immediately after birth. Amplitude integrated electroencephalogram and auditory brainstem evoked potential were abnormal. No pathogenic variations accounting for the phenotypes of the patient were found by whole exome sequencing. Two compound heterogenous mutations in AGRN gene were identified. The baby was hospitalized for 8 days and died on the day of her own discharge. Conclusions　The diagnosis of neonatal M?bius syndrome is still based on clinical manifestations. There may be other developmental abnormalities or syndromes. Comprehensive rehabilitation treatment should be started as early as possible to improve prognosis.

Key words: 　M?bius syndrome;　cranial nerve;　neonate