Coronaviruses (CoVs) (order Nidovirales, family Coronaviridae, subfamily Coronavirinae) are responsible for respiratory disease outbreaks in many vertebrate species. They are a large family of single-stranded RNA enveloped viruses (+ssRNA) that can be isolated in different animal species. They have genome sizes ranging between 26 to 32 kilobases (kb) in length, being the largest genomes for RNA viruses (consequently increasing the effectiveness of facemasks). COVID-19 also known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), 2019-nCoV or "novel coronavirus 2019" is a new virus with no known resistance in humans.
COVID-19 is similar to severe acute respiratory syndrome (SARS) in the respect that both viruses infect their human hosts via the same receptor, the angiotensin-converting enzyme 2 (ACE2 receptor), and cause similar clinical and pathological features. Interestingly the spike protein which is responsible for receptor binding is highly similar between 2019-nCoV and SARS-CoV, this is a result of significant selection for the same receptor (Wu., 2020).
Research into how our bodies defend against other viruses has revealed several strategies our bodies may use to protect us from covid-19. Based on current infections we know that some individuals are virtually unaffected, they can be asymptomatic, while sadly the covid-19 virus has proven to be fatal for thousands of people especially those who are vulnerable.
If you have taken an at home DNA test like those available from 23andMe, Ancestry DNA, Dante labs and other providers including DNA Romance. In this post information is presented a candidate gene for SARS-CoV resistance.
How to analyze your DNA for coronavirus resistance and susceptibility markers?
Step 1) Download your raw autosomal DNA file and save it to a safe and secure location
To analyze your DNA data, start by downloading your raw autosomal DNA and save it to a safe location. Here are instructions to download your raw DNA file from: 23andMe, Ancestry DNA, Family Tree DNA, Dante Labs, My Heritage, Genes For Good, Vitagene, and Living DNA.
Step 2) Analyze your raw DNA file
It simple to manually search your raw DNA data using a text editor such as "text wrangler" or "notepad" using the "find" function
Open the raw DNA file and your will notice the headers of unique SNP ID (rs# or i#), chromosome, position and genotype. The formats differ slightly between each DNA testing company
To evaluate your risk of poor recovery from the coronavirus SARS, HIV, tuberculosis have a look for this SNP:
The SNP rs4804803 can prevent the gene expression of the Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin protein, DC-SIGN for short and in humans the CD209 gene encodes this protein where the G allele is associated with transcription factor binding, and the A allele with its absence (Sakuntabhai et al., 2005). For rs4804803 the G alleles (A:G) or (G:G) have 2.5x greater greater chance of having lower lactate dehydrogenase (LDH) levels compared with -336AA patients. High LDH levels are known to be an independent predictor for poor SARS clinical outcome, possibly because of the increased tissue destruction that is the result of immune hyperactivity. Thus, SARS patients with the AA genotype have a 60% greater chance of a poor prognosis than GG or AG patients, for more details see Chan et al., 2010.
Other DNA markers covered in this post include SNPs positioned in the angiotensin-converting enzyme-2 (ACE2) receptor which was proved to be the receptor for the human respiratory coronavirus NL63 (Li et al., 2017, SARS-coronavirus (SARS-CoV), and the novel coronavirus 2019-nCoV/SARS-CoV (Lu et al., 2019). Since the spike protein of the coronavirus has evolved to match the ACE2 receptor (Wu., 2020), it's likely that individuals with variations that alter the protein sequence would result in a degree of resistance to covid-19. Below non-synonymous SNPs from the ACE2 transcript NM_021804.2 are presented from Cao et al., 2020. Of particular interest are the 3 SNPs highlighted in red which cause major changes to the ACE 2 receptor, rs199951323 results in a premature stop codon, it’s hoped that alleles in the "ALT" category would result in some degree of covid-19 resistance since the virus would find it more difficult to bind to the hosts cells.
|dbsnp||Chromosome||POS||REF||ALT||Function||Transcript NM_021804.2 (3'-5' on genome)|
|rs748163894||chrX||15570311||G||A||missense_variant||Change to transcript NM_021804.2|