Late-onset Wilson Disease in a Patient Followed-up for Nonalcoholic Fatty Liver Disease.

A 73-year-old woman was referred to our hospital for persistent liver dysfunction. When the patient was 45 years old, her youngest sister had been diagnosed with Wilson disease (WD). The patient therefore underwent several family screening tests, all of which were unremarkable. She had an annual medical checkup and was diagnosed with liver dysfunction and fatty liver at 68 years old. A liver biopsy and genetic testing were performed, and she was diagnosed with WD; chelation therapy was then initiated. In patients with hepatic disorders and a family history of WD, multiple medical examinations should be conducted, as the development of WD is possible regardless of age.

Genotype-phenotype variable correlation in Wilson disease: clinical history of two sisters with the similar genotype.

BACKGROUND: Wilson disease (WD) is an Autosomal-Recessive disorder due to mutations of ATP7B gene on chromosome 13q14.3. Inadequate protein function leads to low ceruloplasmin blood levels and copper accumulation in liver, basal ganglia and chornea. Main clinical manifestations are hypertransaminasemia, tremors, dysarthria, dystonia and psychiatric symptoms. The phenotypic variability in WD is considerable and its onset can be heterogeneous: the most common type in childhood is the hepatic involvement, followed by the neurological one or others. The presence of a genotype-phenotype correlation has not yet been fully demonstrated. The phenotypic variability may be explained by the intervention of other modifier genes regulating copper metabolism in the presence of mutations ATP7B. CASE PRESENTATION: A streaking phenotypic variability was observed in two Sicilian sisters carrying the same genotype for ATB7B gene [c.3207C > A / c.3904-2A > G]. Although both started to present signs at age 10 years, onset was characterized by neurological signs in the first (tremors, motor incoordination, language and cognitive impairment), while liver involvement has been the only sign in the other. They started the same chelation therapy. After a 20-year follow-up the former is severely affected (MRI evidence of basal ganglia copper deposits and hyperchogenic liver, thrombocytopenia), while the latter presents only a moderate liver enlargement. In literature, the splice mutation c.3904-2A > G is also reported in Egypt population, associated with acute liver failure or chronic hepatic disease, and it could be typical of Mediterranean area, not being reported in other geographical zones. CONCLUSION: Based on our clinical experience in Eastern Sicily, there is a considerable phenotypic variability in WD, even in the presence of an identical genotype. The mutation c.3904-2A > G could be associated with this phenotypic variability in Mediterranean population, but further studies should be conducted. This condition could be explained by the intervention of modifier genes regulating copper metabolism in the presence of defective ATP7B protein function. Further investigations on their role by Next Generation Sequencing or Whole Exome Analysis might have a profound impact on patients' management and in particular on therapy.