OBJECTIVETo investigate the molecular genetic mechanism of a Chinese patient with mucopolysaccharidosis type I (MPS I).

METHODSPCR-sequencing analysis was applied to detect the mutations in exons in alpha-L-iduronidase gene (IDUA) of the patient. Restriction fragment length polymorphism (RFLP) and allele-specific oligonucleotide hybridization (ASO) were used to confirm the identified mutations. PCR amplified DNA samples from 50 normal individuals were sequenced to demonstrate that the newly identified mutation was not polymorphism.

RESULTSThe patient was compound heterozygous for a previously reported nonsense mutation Q60X (178C > T) in exon 2, inherited from the mother, and a newly detected missense mutation D203N (607G > A) in exon 6 from the father. The newly identified mutation D203N was not found in PCR amplified products from 50 normal individuals, indicating that it was not polymorphism.

CONCLUSIONThe two identified mutations may be the cause resulting in patient's clinical phenotype.