<prompt> Deletion of both Rb retinoblastoma genes in the same developing cell is most characteristically associated with the development ofBlue scleraNo irisSubluxed lensWhite pupil  <response>: Retinoblastoma is the most common malignant tumor of the eye in children. Clinically, retinoblastoma may produce a white pupil leukocoria. This is seen most often in young children in the familial form of retinoblastoma, which is due to a deletion involving chromosome 13. These familial cases of retinoblastoma are frequently multiple and bilateral, although like all the sporadic, nonheritable tumors they can also be unifocal and unilateral. Histologically, rosettes of various types are frequent similar to neuroblastoma and medulloblastoma. There is a good prognosis with early detection and treatment; spontaneous regression can occur but is rare. Retinoblastoma belongs to a group of cancers osteosarcoma, Wilms tumor, meningioma, rhabdomyosarcoma, uveal melanoma in which the normal cancer suppressor gene antioncogene is inactivated or lost, with resultant malignant change. Retinoblastoma and osteosarcoma arise after the loss of the same genetic locus--hereditary mutation in the q14 band of chromosome 13. In contrast, a blue sclera can be seen with osteogenesis imperfect, while a yellow sclera is seen with jaundice. Lack of an iris aniridia can sometimes be associated with Wilms tumor of the kidney, while a subluxated lens can be found in individuals with either Marfans syndrome or homocystinuria. 