Hereditary retinoblastoma transmitted by maternal germline mosaicism

Abstract

Our findings indicated that mosaicism was restricted to the maternal germline. The mutational event must have occurred at least 4 weeks post-conception, unlike the early mutational events of most mosaics, occurring between fertilization and the 8th day of conception. The implications of these findings are discussed in view that genetic counselling should discriminate between germline mosaicism and de novo events in pseudo-low-penetrant hereditary retinoblastoma.