Abstract: This article reports the clinical features of one case of congenital disorders of glycosylation caused by new mutations of the PMM2 gene and the features of PMM2 gene mutation(PMM2-CDG). The child was a 9-month old girl who presented with psychomotor retardation, abnormal liver enzyme, large ears, esotropia of left eye and hypermyotonia. Two heterozygous mutation points in the child's PMM2 gene was found by Sanger sequencing: c.430T> C (p.F144L) in exon 5 and c.556G＞A（p.G186R） in exon 7.The former mutation came from her father and was a known hot-pathogenic mutation, and the latter came from her mother and was a novel mutation unreported. PMM2-CDG should be considered at the presence of multiple organ damage of unknown causes, especially in infants and young children, which is combined with general developmental delay, neurological disease, liver damage, eye abnormalities, and ear abnormalities, etc. The PMM2 gene test is beneficial to accurate diagnosis, The outcome can be evaluated based on the mutation site.

Key words: Congenital disorder of glycosylation, PMM2 gene, New mutation