Multi-ancestry GWAS of diarrhea during acute SARS-CoV2 infection identifies multiple novel loci and contrasting etiological roles of irritable bowel syndrome subtypes (preprint)

A substantial proportion of acute SARSCoV2 infection cases exhibit gastrointestinal symptoms, yet the genetic determinants of these extrapulmonary manifestations are poorly understood. Using survey data from 239,866 individuals who tested positively for SARSCoV2, we conducted a multi-ancestry GWAS of 80,289 cases of diarrhea occurring during acute COVID19 infection (33.5%). Six loci (CYP7A1, LZFTl1/CCR9, TEME182, NALCN, LFNG, GCKR) met genomewide significance in a trans-ancestral analysis. The top significant GWAS hit mapped to the CYP7A1 locus, which plays an etiologic role in bile acid metabolism and is in high LD (r2= 0.93) with the SDCBP gene, which was previously implicated in antigen processing and presentation in the COVID-19 context. Another association was observed with variants in the LZTFL1/CCR9 region, which is a known locus for COVID19 susceptibility and severity. PheWAS showed a shared association across three of the six SNPs with irritable bowel syndrome (IBS) and its subtypes. Mendelian randomization showed that genetic liability to IBS-diarrhea increased (OR=1.40,95%,CI[1.33,1.47]), and liability to IBS-constipation decreased (OR=0.86, 95%CI[0.79,0.94]) the relative odds of experiencing COVID19+ diarrhea. Our genetic findings provide etiological insights into the extrapulmonary manifestations of acute SARSCoV2 infection.

The UGT2A1/UGT2A2 locus is associated with COVID-19-related anosmia (preprint)

Loss of sense of smell is a characteristic symptom of infection with SARS-CoV-2. However, specific mechanisms linking infection with loss of smell are poorly understood. Using self-reported symptom data from the 23andMe COVID-19 study, we describe the demographic patterns associated with COVID-19 related anosmia, and find the symptom is more often reported in women and younger respondents, and less often by those of East Asian and African American ancestry compared to those of European ancestry. We ran a trans-ethnic genome-wide association study (GWAS) comparing loss of smell or taste (n=47,298) with no loss of smell or taste (n=22,543) among those with a positive SARS-CoV-2 test result. We identified an association (rs7688383) in the vicinity of the UGT2A1 and UGT2A2 genes (OR=1.115, p-value=4x10-15), which have been linked to olfactory function. These results may shed light on the biological mechanisms underlying COVID-19 related anosmia.

Trans-ethnic analysis reveals genetic and non-genetic associations with COVID-19 susceptibility and severity (preprint)

COVID-19 presents with a wide range of severity, from asymptomatic in some individuals to fatal in others. Based on a study of over one million 23andMe research participants, we report genetic and non-genetic associations with testing positive for COVID-19, respiratory symptoms, and hospitalization. Risk factors for hospitalization include advancing age, male sex, elevated body mass index, lower socio-economic status, non-European ancestry, and pre-existing cardio-metabolic and respiratory conditions. Using trans-ethnic genome-wide association studies, we identify a strong association between blood type and COVID-19 diagnosis, as well as a gene-rich locus on chr3p21.31 that is more strongly associated with outcome severity. While non-European ancestry was found to be a significant risk factor for hospitalization after adjusting for socio-demographics and pre-existing health conditions, we did not find evidence that these two primary genetic associations explain differences between populations in terms of risk for severe COVID-19 outcomes.