True about retinoblastoma are all except :

Retinoblastoma Incidence:  It is the most common intraocular tumor of childhood occurring 1 in 20,000 live births. Age : though congenital, it is not recognized at birth, and is usually seen between 1 and 2 years of age. Sex : There is no sex predisposition. Race : it is rarer in Negroes than whites. Bilaterality : In 25-30% cases, there is bilateral involvement, although one eye is affected more extensively and earlier than the other.