When a gene is expressed, it is first transcribed (DNA → mRNA) and the mRNA is then translated into a protein. Not all genes in the genome are expressed in all cells or tissues, because the need and function of various cells or tissues differ. Therefore, the consequences of a gene mutation will primarily affect tissues relying on and expressing that specific gene. Techniques for detecting gene expression are for example, northern blot, quantitative PCR, and microarray.

Linkage analysis DNA sequencing

Theory Overview