Autosomal recessive 333 base pair interleukin 10 receptor alpha subunit deletion in very early-onset inflammatory bowel disease

Figure 1 Identification of a novel 333-bp deletion spanning interleukin 10 receptor alpha subunit exon1. A: Perianal skin tag; B: Endoscopic image of ulcerations; C: Sanger DNA sequencing verified a compound heterozygous variant (c.537G>A) inherited from the mother in patient B; D: Whole-genome sequencing (WGS) data showing sequencing read pairs at breakpoints chr:117857030 and chr:117857362 of interleukin 10 receptor alpha subunit (IL10RA); E: Polymerase chain reaction validated the heterozygous deletion of 333 bp spanning exon1 inherited from the father; F: WGS revealed compound heterozygous variants of IL10RA in patient B with very early-onset inflammatory bowel disease. bp: Base pair; HD: Healthy donor.

Figure 2 Schematic diagram of disrupted RNA splicing and 333-bp deletion in interleukin 10 receptor alpha subunit. A: Schematic diagram of disrupted splicing caused by c.537G>A in interleukin 10 receptor alpha subunit (IL10RA) between the boundary of exon4 and intron4; B: Schematic diagram of IL10RA 333-bp deletion. bp: Base pair.

Figure 3 Histopathochemistry and functional results of homozygous interleukin 10 receptor alpha subunit mutation. A: Histological findings in a colonic specimen obtained during colonoscopy showing oval-shaped intramural abscesses; B: Higher magnification of inset A; C: Determination of TNF-α levels in the supernatant of cultured PBMCs from patient D after stimulation with PBS, LPS, or LPS + IL-10 in vitro; D: Western blot results of PBMCs isolated from patient D after stimulation with LPS or IL-10. Phosphorylation of STAT3 at Tyr705 and Ser727 and total STAT3 protein were detected (n = 3). ^aP < 0.05, ^bP < 0.01, and ^cP < 0.001 were considered as statistically different.