This hereditary component is inheriting one of the two “hits” on one of the RB1 alleles, which inactivates the gene. The interesting thing is that hereditary retinoblastoma behaves as autosomal dominant, like I said in the first sentence, in pedigrees, but the disease results from a gene in the loss of heterozygosity, through a somatic mutation, on chromosome 13. The chance to pass it on to a child is 45%, since it is a germline disease (Abramson, 2004). Two research studies have found that there the paternal allele retention is preferential in the loss of heterozygosity. They showed that all ten of ten germline mutations were derived from the paternal allele on chromosome 13, with 4 of 7 of the somatic mutations being on the maternal allele. The researchers hypothesized that mutations may be more common during spermatogenesis due to the DNA methylation or environmental exposure (Zhu et al., 1989)(Dryja et al.,
This hereditary component is inheriting one of the two “hits” on one of the RB1 alleles, which inactivates the gene. The interesting thing is that hereditary retinoblastoma behaves as autosomal dominant, like I said in the first sentence, in pedigrees, but the disease results from a gene in the loss of heterozygosity, through a somatic mutation, on chromosome 13. The chance to pass it on to a child is 45%, since it is a germline disease (Abramson, 2004). Two research studies have found that there the paternal allele retention is preferential in the loss of heterozygosity. They showed that all ten of ten germline mutations were derived from the paternal allele on chromosome 13, with 4 of 7 of the somatic mutations being on the maternal allele. The researchers hypothesized that mutations may be more common during spermatogenesis due to the DNA methylation or environmental exposure (Zhu et al., 1989)(Dryja et al.,