Outline the stages needed to prepare an individual's genome so that it is ready to be examined with a microarray chip.
DiGeorge syndrome is a dominant inherited disorder in humans. It results from a deletion of a large number of nucleotides from chromosome 22. The number of nucleotides lost differs between individuals and lies between $800\,000$ and $3\,100\,000$. The largest deletions may remove as many as $46$ protein-coding genes from the chromosome. Fig. 4.1 shows the outcome of aCGH with a microarray specific to the region of chromosome 22 where the DiGeorge syndrome deletion is located. The microarray compared DNA from two individuals: one affected by DiGeorge syndrome and one without DiGeorge syndrome (control DNA used for comparison).
Using Fig. 4.1 as your reference, estimate the number of nucleotides deleted from the affected chromosome 22 in the individual with DiGeorge syndrome. Give the answer to the nearest $100\,000$ nucleotides.
Explain how the microarray method works to produce the results shown in Fig. 4.1.
Using Fig. 4.1 as your reference, estimate the number of nucleotides deleted from the affected chromosome 22 in the individual with DiGeorge syndrome. Give your estimate to the nearest $100\,000$ nucleotides.
Explain how the microarray technique operates to generate the results shown in Fig. 4.1.
Suggest why the phenotypes of two individuals with DiGeorge syndrome may differ.