Hi
I am working on cancer genomics. In studying copy number change of matched samples of pre and post chemotherapy from the same patient what does copy number states AA, AAB, AABB, AAA, and AAAA mean?
The number of As and Bs stand for the number of alleles from each parent. Normal cells have one allele of each autosome from each parent, so the chromosomes 1-22, and all locations on those chromosomes are all AB.
Normally you don't know which allele came from the mother and which allele came from the father. You code any changes with more As than Bs.
A region with AAB is triploid, and still has alleles from both parents. Usually this has only moderate effects, if any. In general it takes amplification of a region (10 or more copies) for real dosage effects.
AABB is a doubling of both alleles, this can happen during cell division, in the G2 phase.
With states A, AA, AAA, and AAAA there is LOH, loss of heterozygosity, with varying amounts of duplication of the remaining allele. This can be used to determine tumor suppressor genes.
Use of this site constitutes acceptance of our User Agreement and Privacy Policy.
version 2.3.6
Are you able to see table 12.1?
Thank you @genomax, table gave me a very good intuition to start understanding
Your organism is diploid by default. AA means that both alleles are A. AB means heterozygous allele (normal). BB means the same as AA but since there is no general rule how you denote alleles people write AA. AA is loss of heterozyosity. AAB = duplication. AABB = tetra ploidy (2 copies of one allele and 2 copies of another). And so on. Hope it is understandable :)