LAUSR

manifestations that are markedly different between IIIA and IIIB: Hepatosplenomegaly and serrated teeth. The most common initial symptoms at diagnosis were speech delay (52.94%), hyperactivity (35.29%), and mental deterioration (29.41%). Genetic analysis of 25 patients was conducted, which identified 12 previously unreported mutations. There was no significant difference in the incidence of MPS IIIA and IIIB in this Chinese cohort. The incidence of MPS IIIC was significantly lower than that of IIIA and IIIB. No IIID patient was found. The initial clinical symptoms of MPS III were atypical. When language retardation, mental retardation, and rough facial features occur, MPS III should be considered in combination with other clinical features, such as cerebral cortex atrophy. Hepatosplenomegaly and serrated teeth can be used clinically to preliminarily distinguish IIIA from IIIB. We emphasize the importance of establishing early diagnostic procedures so that gene therapy can be carried out as soon as possible to alter the disease prognosis.