[Detection of a new mutation (T1140C)in a Chinese Guangdong patient with hunter syndrome].

To identify mutations of iduronate-2-sulfatase (IDS) gene in a patient with Hunter syndrome and to establish a basis for prenatal gene diagnosis of Hunter syndrome. Urine GAG assay was used for preliminary diagnosis of mucopolysaccharidosis. PCR from dried blood spots and DNA sequencing were applied to analyze hot spot mutations in exons 9, 3, 8 of the IDS gene in the proband and his parents. A new missense mutation (T1140C) in exon 8 of the IDS gene was found by DNA sequencing. This mutation caused a substitution of codon 339 from CTA (leucine) to CCA (proline). The patient is a hemizygote and his mother is a heterozygote. The new missense mutation results in a change in the primary and tertiary structure of the IDS protein. It is possible that this mutation severely impairs the enzymatic activity and is the underlying basis for the pathology seen in this patient with Hunter syndrome.