IL10RB and inflammatory bowel disease: 38 Another case report described three patients with IBD and homozygous loss of function of the IL10RB locus: two patients with homozygous deletions and a patient with a heterozygous deletion and a duplication causing a frameshift loss-of-function mutation.39 Recently, a genome sequencing identified a 12.3 kb homozygous tandem duplication that disrupted the reading frame of the LRBA gene.40