This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
A young patient present with significant loss of central vision and a normal ERG. There is no obvious family history of similar presentation. The most likely diagnosis - 
Select and explain. 
A. Best's disease, B. Stargardt's disease, C. Retinitis Pigmentosa, D. Cone Rod Dystrophy
B: Stargardt's disease
Answer: B: Stargardt's disease 
Explanation: Loss of central vision along with a normal ERG is consistant with a diagnosis of Best's disease and stargardt's disease. Absence of a positive family history favours a diagnosis of stargardt's disease.
Stargardt's disease being an autosomal recessive disorder may not reveal a positive family history. Best's disease, being an autosomal dominant disorder should have a positive family history.