Objectives: To study the feature of disease-causing mutation of exon 12 of Wilson disease (WD) gene in Chinese and evaluate its value in direct gene diagnosis.
Methods: Genomic DNA of 44 unrelated WD patients and 60 normal controls was prepared from peripheral blood leukocytes by a salt-out method. The mutation of exon 12 in these subjects was identified by PCR-single strand conformation polymorphism (SSCP) and further confirmed by direct sequencing.
Results: Two missense mutations were identified in 8 cases (18%), including 6 cases of heterozygous for Thr935Met mutation and 2 of heterozygous for Gly943Asp mutation. Different features of mutation of exon 12 were noted between Chinese and Caucasian. Both Thr935Met and Gly943Asp were novel missense mutations and exon 12 was another hot point mutation of WD in Chinese besides exon 8.
Conclusion: The finding helps establish a fast and effective direct gene diagnosis.