You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Regarding retinoblastoma all of the following are true, EXCEPT: and explain in detail?
Hereditary retinoblastoma accounts for 40% of cases. All bilateral and cases and about 15% of the unilateral cases are hereditary. Retinoblastoma gene has been identified as 14 band on the long-arm of chromosome 13 (13q14). Deletion or inactivation of this protective gene by two mutations results in occurrence of retinoblastoma. Inheritance is autosomal dominant and the risk of transmitting the gene mutation is 50%. Because of high penetrance 40% of offspring of a surviver of hereditary retinoblastoma will develop the tumor. 33% are bilateral (1/3rd cases). Ref: Ophthalmology by A K Khurana 4th edition, Page 280