Question

Explain the technology behind DTC genetic kits. Include a breif but precise technical description of how microarrays work. How are the data analyzed and interpreted. What are haplotypes.

Answer 1

1. Direct to consumer genetic testing is different from usual testing is because DTC genetic testing marketed directly to costumers through television, print advertisements, or the internet, and the test can be bought online or in stores. Costumers send a DNA sample to the company and they get the result directly from the website or as a written report. There are so many companies offer DTC genetic tests for different purposes. Simply DTC genetic testing is marked directly to the consumers there is no involvement of health care provided. This generally request there costumers to collect specimens, (saliva or urine,) and send it to the company for further testing and analysis. Not all consumer testings are genetic test some measures toxins or proteins or bacteria in the sample there by in body.

Not all direct-to-consumer genetic test companies test for the same set of variants, and therefore may provide different results for the same disease or condition. Therefore, consumers must use their judgment when ordering and interpreting their results from these tests. Consumers should consider discussing their results with a genetic counselor or a qualified health care provider to better understand the clinical relevance of the result to their own health.

2. DNA microarray is a chip it contain collection of DNA spots. IT is widely used to study expression of large numbers of gene simultaneously, or to genotype multiple regions of the a genome. Microarray is a collection of microscopic features which can be probed with target molecules to produce either target molecules to produce either quantitative or qualitative data. Here the target is unknown sequence. The probes synthesized and immobilize as a discrete spots. Each spot contains millions of identical probes. The protein of interest or target protein is fluorescently labele and then hybridize to the probe in the spot. The hybridization will result change intensity of fluorescence. That we can measure using a flourascence scanner.

3. To determine which genes are turned off and which gene is turned on in a given cell , a researcher first have to collect mRNA molecules present in that cell. Then need to label with fluorescent dyes and place on microarray. The mRNA present in cell will hybridize with DNA complementary to it. If a particular, gene is active and because of more mRNA, it will give bright fluorescents. Genes inactive give less mRNA and give dim fluorescents. Inactive region is marked by no fluorescents.

4. Hapalotype means a set of Polymorphisms or DNA variations and that tend to be inherited together. They are found on same chromosome. They are very close together so the recombination frequency is very less. One example is the MHC gens.