Causes of Best's disease

Best disease is an inherited disease with an autosomal dominant pattern of inheritance. In this inheritance pattern, a person is affected if one of the two copies of the Best gene is abnormal. The Best disease gene is also called VMD2 and is located on chromosome 11q13.

The children of an affected person have 50 percent chance to inherit the abnormal copy of the Best disease gene. A child who inherited the normal copy of the Best disease gene will not have the disease and will not pass the disease to his or her children.

The severity of Best disease, however, is very variable among affected individuals. Most individuals with VMD2 mutations have an abnormal electro-oculagram (EOG), but the macular appearance may be normal in some. There is only one individual reported with evidence of non-penetrance, in that he is a carrier of a VMD2 mutation but has a normal fundus and normal EOG.