Intriguingly, these risk variants were observed to be associated with subphenotypes of IgAN, i.e., early age at onset, elevated Gd-IgA1 levels, severe hematuria, and advanced chronic kidney disease (CKD) stage., and in a concordant way, specific risk genotypes in IgAN were associated with decreased abundances of potentially beneficial microbes and increased abundances of potentially harmful microbes, as reported for IBD. The gene discussed is IGHA1; the disease is chronic kidney disease.