Chapter 26.3, Problem 1QTC

Summary Introduction

To determine:

The benefits of using a DNA microarray over a genetic marker such as a STR.

Given:

Gene microarray technology rests on the ability to deposit many (tens of thousands) different DNA sequences on a small surface, usually a glass slide (often referred to as a “chip”).

Introduction:

With the development of new technologies for more accurate understanding of the genome and potential gene therapies, the detection of mutations has an increasingly central role in various areas of genetic diagnosis including preimplantation genetic diagnosis (PGD), prenatal diagnosis (PND), presymptomatic testing, conformational diagnosis and forensic/identity testing. Two groups of tests, molecular and cytogenetic, are used in genetic syndromes. In general, single base pair mutations are identified by direct sequencing, of DNA hybridization and/or restriction enzyme digestion methods. However, there are two approaches for genetic diagnosis; indirect approach depends on the results from a genetic linkage analysis using DNA markers such as STR (short tandem repeat) or VNTR (variable number tandem repeat) markers flanking or within the gene. On the other hand, the direct approach for diagnosis essentially depends on the detection of the genetic variations responsible for the disease.