In a survey in Israel of 50 patients with Wilson's disease, it was found that 
this disease occurred in all ethnic groups. In the Arab patients there was a 
significantly early age of onset and the disease followed a more severe course 
than that in the Jewish patients. The overall sex ratio of patients was nearly 
1:1, and genetic analysis of 20 families confirmed an autosomal recessive mode 
of inheritance. The very similar age of onset and type of disease within 
sibships and the varying ages of onset noted between the Arab and Jewish 
patients suggest that the disease is genetically heterogeneous.