Genetics Testing

examines DNA from cells and identifys markers for diseases

DNA change can be large enough

Gene expression, deletion can be abnormal

switched or transposed

Gene test for predisposition of disorder and abnormal arrangement of chemical bases

metabolism errors protein abscences

Carrier testing can help couples to tear if they carry dangerous alleles

biochemical, chromosonal, DNA bases

Downs Syndrome, Achondroplasia

DNA in cancerous cells

diagnosis,early detection, gene survellance

Prognosis - mutated p53 tumour suppressor flags aggressive cancer

Treatment - antibodies block genes

Faulty inherited genes can be detected

mutated genes

Retinoblasta - eye cancer

Wilms tumour - kidney cancer

L1 Fraument - lots of child cancers, FAP precancerous polyps look for genetic markers

DNA probe linked to radioactive atom/Single strand probe seeks and binds to gene

Radioactive signals made, show where gene  and probe matched

DNA broken up into different sizes

Autoradiograph - identify target genes

Microarray indicate level of gene expression

A negative test can provide relief

A positive test relieves uncertainty and can be intervened, improve cancer diagnosis and treatment allow decisions to be made

Limitation - test deal in probabilities

Psychological impact

medical choices

privacy

family relations