ARSA Gene Mutation In Metachromatic Leukodystrophy Patients

Objective To identify arylsulftase A gene(ARSA)mutations in 8 patients of MLD.So as to find out molecular genetics etiological factor in the patients.Methods There were 8 MLD patients in the investigation.4 patients were diagnosed late-infantile MLD and other 4 patients were diagnosed juvenile MLD.Among 4 late-infantile MLD two patients are twins and among juvenile MLD two patients are sibling.Genomic DNA samples were extracted from peripheral bloods of the patients and all her family members.All 8 exons and exon-intron boundaries of ARSA gene were amplified by polymerase chain reaction(PCR)and followed by direct DNA sequencing.Look for the causive mutation and validate novel mutation.Then analyse the relation between genotype and phenotype.Results 8 kinds of mutation were identified in the 8 patients.4 mutations(c.887G＞T/c.911C＞r and c.179₁80dupCA,c.1338dupC)are novel mutation.4 mutations(c.251G＞A/c.296G＞T and c.954G＞A,c.862C＞T)are known mutation.Conclusion 3 patients(including 2 twins)are homozygous mutation c.954G＞A and phenotype is late-infantile MLD.One patient is compound heterozygous mutation c.887G＞T/c.911C＞T and phenotype is late-infantile MLD.Two patients are sibling and their genotype are all c.251G＞A/c.296G＞T,their phenotype is juvenile MLD.One patients is compound heterozygous mutation c.862C＞T/c.1338dupC and phenotype is juvenile MLD.The last patient is juvenile MLD and we only identified one mutation c.179₁80dupCA.