??? ??? ?? ? ? ?? ?? ??? ????? ??? ?? ??? ???? ??? ???? ?????.???? ??? ? ?? ??: ??? ??? ???? ???? ??? ? ????.A chromosomal abnormality consisting of the absence of one of several copies of chromosome seven in somatic cells. [from NCI]Retinoblastoma is usually a malignant tumor on the creating retina that happens in kids, ordinarily just before age