Nonheritable Retinoblastoma

The genomic landscape of retinoblastoma is driven by alterations in RB1 that lead to biallelic inactivation.[5,6] A rare cause of RB1 inactivation is chromothripsis, which may be difficult to detect by conventional methods.[7]

Recurrent changes in genes other than RB1 are uncommon in retinoblastoma but do occur. Variants or deletions of BCOR and amplification of MYCN are the most frequently reported events.[5-10] A study of 1,068 unilateral nonfamilial retinoblastoma tumors reported that 2% to 3% of tumors lacked evidence of RB1 loss and approximately one-half of these cases without evidence of RB1 loss showed MYCN amplification.[6] However, MYCN amplification is also observed in retinoblastoma tumors that have RB1 alterations, suggesting that inactivation of RB1 by a variant or an inactive retinoblastoma protein is a requirement for the development of retinoblastoma, independent of MYCN amplification.[11]

For information about the treatment of retinoblastoma, see Retinoblastoma Treatment.