Abstract: Objective：To investigate the clinical characteristics and gene information of Xia-Gibbs syndrome with AHDC1 mutaiton. Methods：A boy diagnosed of Xia-Gibbs syndrome confirmed by whole-exon sequencing (WES) which revealed a de novo mutation in AHDC1 was reported. His clinical data and gene mutation was summarized combined with cases retrieved from the related literatures. Results：This patient was first send to our clinic because of global development delay. He had no verbal words and was unable to creep. He had low-set ears and esotropia in left eye. Hypotonia was noted on physical examination. Patent foramen ovale (PFO) was detected by echocardiogram, and hydronephrosis (HN) was noted by renal ultrasound. Magnetic resonance imaging of brain revealed less white matter, thin corpus callosum. Bilateral and high amplitude delta waves was shown though an electroencephalogram. Whole exon sequencing indentied a de novo deletion mutation in AHDC1: c.750_753delCCTC, which probably leads to an even earlier stop of translation（p.T252Afs*7）.A total of 15 cases was retrieved from 6 literatures analyzed with AHDC1 mutation. The clinical phenotypes in all the effect individuals were dominated by mental retardation, mild craniofacial dysmorphism, hypotonia, respiratory and sleep disorders. Other similar medical features contained ataxia, epilepsy, autism, feeding difficulties and visual impairment. Thin corpus callosum was the majority brain anomaly observed by neurologic images. Totally 13 mutation sites had been reported and the most common type was truncating. Conclusion：Xia-Gibbs syndrome with AHDC1 mutation was characterized by severe mental retardation, facial dysmorphia，hypotonia and sleep apnea. Further functional expression still should be done to explore whether AHDC1 mutation plays a role in the cause of the PFO and hydronephrosis.