SARS-CoV has an RNA genome that is categorized in the family
<i>Coronavirida</i>e and the order <i>Nidovirale</i>s. Similarly, Severe Acute Respiratory
Syndrome Coronavirus-2 (SARS-CoV-2) also belongs to this family and order. A
significant degree of variability was observed in SARS-CoV-2 in individuals, which
could be influenced by genetic variations in the host. This may impact the progression
of sickness and the efficacy of treatment approaches. Individuals who carry certain
mutants of genes (ACE2 and TMPRSS) directly linked to viral illness or who have a
distinctive expression of those genes may be more vulnerable (SARS-CoV-2). These
alterations may explain the enormous diversity of symptoms and severity of
Coronavirus Disease-19 (COVID-19)-related disease in various people. Regarding
variation, the D614G spikes gene is the most varied among hosts. Moreover, single
nucleotide polymorphism (SNP) and single nucleotide variants (SNVs) are causes of
host genetic diversity, according to some studies. The structure of SARS-CoV is made
up of structural and accessory proteins. These accessory proteins (3a, 3b, 7b, ORF, etc.)
show missense mutations in their sequence. Both types of proteins undergo rapid
mutations. Point mutations and genetic recombination of SARS-CoV participate in its
adaptations and variations among hosts of different species. Middle East Respiratory Coronavirus (MERS-CoV) and SARS-CoV-1, SARS-CoV-2 have striking differences
among their proteins. Mannose-binding protein (MBL) takes part in countering viral
infections. A decrease in MBL increases the exposure of host cells to SARS-CoV
infections.