The clinician requested HNF1A and HNF4A gene mutations genetic testing once analysing previous results. Before any further analysis could go ahead, the patient had to give consent for the genetic analysis having been briefed on the tests being performed and possible consequences.
Once consent was given, blood samples were taken in Craigavon Area Hospital by a registered nurse via venepuncture, using a tourniquet and an 18 gauge butterfly needle, collected into sterile purple topped blood tubes with added EDTA anticoagulant. A minimum of 10ml of blood was required, so three EDTA tubes were filled. In an attempt to monitor pre-analytic variables, the patient would have been advised to relax their arm while the bloods were …show more content…
The requester had to ensure they completed the form electronically and to send a printed copy along with the sample, ensuring the details on both the samples and the two request form were the same. (Example of the Genetic Test Request form is included in Appendix 1.) Once the electronic form was sent, the paper copy and the blood samples were sent to Craigavon specimen reception in the laboratories via porter where they were sorted, processed and checked before transfer to the Royal Devon and Exeter Hospital …show more content…
Sanger sequencing methodologies used for the HNF1A and HNF4A gene analysis is referred to as ‘first’ generation DNA sequencing and allows for the clinical determination of the order in which the bases appear in a given strand of DNA known as a gene.
Test methodologies for analysis of the HNF1A gene consisted of analysis of all the coding regions and the exon-intron boundaries regarding that specific gene. This was carried out by a DNA sequencing method known as Sanger sequencing Exeter laboratories on ABI PRISM 377 DNA Sequencer analyser. Likewise, the investigations carried out on the HNF4A gene was also carried out by the Sanger sequencing method. This time carrying out investigations of the P2 promoter region, as well as associated exon-intron boundaries of the HNF4A gene.
The ABI PRISM 377 DNA Sequencer is an automated instrument designed primarily for the analysis of fluorescently-labelled DNA fragments separated by gel electrophoresis. Gel electrophoresis is the method used to separate the DNA based on their size as the charged molecules migrate through a polyacrylamide gel when an electric current is