Mutations in the gene rb retinoblastoma affects which...

Mutations in the gene Rb (retinoblastoma) affects which hallmark of cancer? Self-Sufficiency in Growth Signals Insensitivity to Antigrowth Signals Limitless Replicative Potential Tissue Invasion and Metastasis

Transcript

00:01 The question is randy has been inherited with a form of eye cancer called as retinoblastoma.

00:16 Why and how does this disease is inherited? retinoblastoma is because of the rb gene.

00:25 So basically how did he inherit this disease? and the option given are first is loss of heterozygosity so this could be the reason last of heterozygosity is where so when retinoblastoma occurs at that time both allel should be mutant with there should be mutation in the both the allel of rb genes so loss of heterozygosity is when sometimes one allele is normal and one allele is mutant still it will be functional with no effect and when both the allel become mutant, that means the heterocycocity.

01:15 This was heterozygotity.

01:16 This has become lost now and the allel is no more functional.

01:20 So this is loss of heterozygotity causing the disease.

01:24 So this is a possibility.

01:26 Yes.

01:26 Let's see the further option.

01:29 B option says that germline mutation in both rb elite.

01:34 So germline mutation is also correct because it is inherited.

01:43 Of disease correct so it should happen in the germline mutation also but let's see the further options third is germline dominant gain of function so here again there is germline mutation which is dominant mutation and there is a gain of function in rb gene and somatic mutation in other allele so there is a gain of function in rb one of the r b allele and second will have a somatic mutation so this is also possible as i said there should be two mutations so that both the alleles are defective so one can have a gain of function and one can have a somatic mutation so this possible combination is correct fourth option is loss of control over g2 to m checkpoint so there are checkpoints in the cell cycle where cell will check for any errors.

02:50 So when there is a loss during this checkpoint, that time this cancer may occur.

02:57 And fifth option is, that is, e option is both a and c, means both 1 and 3 according to our numbering.

03:09 So we can go with fifth option because loss of heterozygosity is also correct.

03:15 So gain of function of rb allele and somatic mutation in another allel, this is also correct.

03:23 So this is also correct but here more specifically they have not given about what kind of mutation has been occurred.

03:29 Whereas in the third option they have specified the mutation type which gives a more appropriate answer...

Question

Mutations in the gene Rb (retinoblastoma) affects which hallmark of cancer? Self-Sufficiency in Growth Signals Insensitivity to Antigrowth Signals Limitless Replicative Potential Tissue Invasion and Metastasis

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