Biology of Disease

Potential parents in whom a genetic defect is detected must be advised to

have genetic counseling. The advice they are given is based on analyses of

the risks of them having a child with a genetic abnormality or that they may

develop a late onset genetic disease. Information drawn from a wide range

of sources is required in such circumstances and genetic counselors must

provide such information with tact and sensitivity.

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DNA

sample

Gene 1

normal copy

Gene 1

mutation G

Gene 4

mutation H

Gene 4

Normal copy

Apply to microarray

to identify

mutations

A)

Amplification of

four genes by PCR

Fluorescent pattern of spots on the

microarray reveals the extent of

hybridization

Hybridization,

unbound DNA

washed away

B)

Figure 15.38 (A) Schematic to show the use of the polymerase chain

reaction and microarray to amplify genetic material and detect specific

mutations. For clarity, only four genes each with nine (A–I) mutations

have been shown. See texts for details. Redrawn from Klug, WS and

Cummings, MR (2002)Essentials of Genetics, 4th edn, Prentice Hall, NJ,

USA.(B) Detail from a developed microarray. The hybridization of

nucleic acid samples to the probes of the microarray determines the

pattern of fluorescence spots that can be analyzed by a laser. Courtesy

of Dr Q. Wang, School of Biology, Chemistry and Health Science, Manchester

Metropolitan University, UK.