Molecular diagnosis and prophylactic therapy for presymptomatic Chinese patients with Wilson disease.

BACKGROUND The potential for therapy for Wilson disease (WD) emphasizes the importance of presymptomatic diagnosis in families with WD (WD families). OBJECTIVES To investigate the feasibility of presymptomatic DNA diagnosis and evaluate the efficacy of zinc sulfate therapy in WD families. METHODS Seventy-eight clinically unaffected siblings were studied from 51 unrelated WD families that were ascertained by affected individuals. The diagnosis in presymptomatic patients was established by a combination of direct mutational analysis and haplotype analysis with 3 short tandem repeat markers. The presymptomatic patients were treated with 50 mg of elemental zinc sulfate twice a day from the time of molecular diagnosis and followed up for 3 to 5 years. RESULTS Of the 78 siblings, 17 were diagnosed as presymptomatic patients. Kayser-Fleischer rings were absent in 7 and faint in 4 of the 17 presymptomatic patients. The serum ceruloplasmin values gradually increased and 24-hour urinary copper values gradually diminished during zinc therapy, which indicate effective control of copper metabolism. None of the siblings developed clinical symptoms of WD or adverse effects from zinc therapy. CONCLUSION We conclude that presymptomatic DNA diagnosis and zinc therapy are effective treatment of patients with WD.