Abstract: Objective　To investigate the clinical features and gene mutation analysis of Nicolaides-Baraitser syndrome. Methods　The clinical data of a child with Nicolaides-Baraitser syndrome diagnosed in the neurology department of Hunan Children's Hospital were retrospectively analyzed. Using "Nicolaides-Baraitser Syndrome" and "SMARCA2" as keywords, the literatures in database of Wanfang Data Knowledge Service Platform, China National Knowledge Infrastructure (CNKI), National Center for Biotechnology Information (NCBI), and Biomedical Literature Database (PubMed) up to June 2018 were searched, and the clinical manifestations and genetic mutations of children with Nicolaides-Baraitser syndrome were summarized. Results The patient was a boy, admitted to our hospital in April 2018 due to intermittent convulsions started from the age of 1 year and 2 months. The initial manifestation was binocular gaze, the reaction was reduced, no obvious limb shaken, and the duration was tens of seconds. After remission, fatigue and sleep were observed, and his presentation during intermittent period was as usual. Convulsions occurs once about every 10 days and refractory to oral administration of carbamazepine. One month ago, a rapid body shake was occurred and sometimes accompanied by paroxysmal general weakness, with a few seconds of relief, but frequent episodes. Physical examination found head circumference was 44 cm, other features including facial dysmorphism, triangular face, wide and long philtrum, thin upper lip, thicker lower lip, sparse hair on the head, transverse palm of right hand, and normal gait. Gezer Intelligence Scale DQ=57, and EEG showed background rhythm was slow, a large number of spikes and sharp waves in the pillow and crotch area were distributed, an extensive spine waves were distributed in large quantities, full-guided slowwave burst with myoclonic seizures. The onset of focal episodes initiated from the right occipital region and the temporal region were detected once each. The gene mutation analysis revealed a de novo c. 3293 G>A in exon 24 of the SMARCA2 gene on the chromosome 9. The reported mutations in 61 children included in-frame deletion mutations in two cases and missense mutations in 59 cases. Conclusions　Up to date, 75 cases of Nicolaides-Baraitser syndrome have been reported in foreign literatures. This article firstly reports a case of Nicolaides-Baraitser syndrome in China.

Key words: Nicolaides-Baraitser syndrome;　SMARCA2 gene;　 child