[P1-173] The new mutations cause the Sandhoff disease in two Chinese families
[Abstract] Object: To explore the clinical features and molecular mutation of HEXB gene in two cases with infantile Sandhoff disease. Method: We retrospectively reviwed the clinical, neuroimaging and gene of the chidren with infantile Sandhoff disease. The mutations of HEXB gene are investigated by Next-generation sequencing. Result: The two patients presented with heterogenous symptoms of neurologic deterioration. HEX activity in one patient’s leukocytes was severely deficient. We identified four different mutations:c.1652G＞A(p.Cys551Tyr), c.1389C＞G(p.Tyr463*), c.1263_1268delTGAAGT(p.Glu422_Val1423del), c.1614-2A＞G(p.?). Conclusion: The clinical features of infantile Sandhoff disease include progressive neurodegeneration, psychomotor retardation and seizures. The enzyme assay and molecular analysis of HEXB gene can confirm the diagnosis of Sandhoff disease. Our study expands the spectrum ot genotype of SD in China.