Detailed histological findings and results of APC mutation screening in blood and polyp samples of the seven cases with mosaic APC mutations
| Patient ID | Sample ID | Histology | Grade of dysplasia | Localisation of polyps | Truncating APC mutation | Sequencing method (number of mutant reads/read depth=% mutant reads) |
|---|---|---|---|---|---|---|
| (A) Mosaic cases in polyp screening cohort (n=20) | ||||||
| F1243 | L | c.3283C>T; p.Gln1095* | Exome (2/213=1%); Multiplicom (33/1875=1.8%) | |||
| T1 | Tubulovillous adenoma | Low grade | Approximately 50 cm ab ano | Exome (4/35=11%) | ||
| T2 | Tubulovillous adenoma, partly hyperplastic polyp | Low grade | Approximately 40 cm ab ano | Exome (11/39=28%) | ||
| F1543 | L | c.1495C>T;p.Arg499* | Multiplicom (22/17 460=0.1%) | |||
| T1 | Tubular adenoma | Low grade | Rectum | Sanger | ||
| T2 | Tubular adenoma | Low grade | Caecum | Sanger | ||
| T3 | Tubular adenoma | Low grade | Rectum | TruSight (65/364=18%) | ||
| F1676 | L | c.2840_2841delGT; p.Cys947Phefs*15 | Exome (19/220=9%); Multiplicom (129/2149=6%) | |||
| T1 | Tubular adenoma | Low grade | Transverse colon | Exome (16/55=29%) | ||
| T2 | Tubular adenoma | Low grade | Caecum | Exome (45/130=35%) | ||
| T1 | c.4348C>T;p.Arg1450* (second hit?) | Exome (6/34=18%) | ||||
| F5000 | L | mutation not detectable | Exome (0/67=0%); Multiplicom (0/2650=0%) | |||
| T1 | Tubular adenoma | Low grade | Descending colon | c.4127_4128delAT; p.Tyr1376Cysfs*9 | Exome (2/3=67%) | |
| T2 | Tubular adenoma | Low grade | 13 cm distal from valvula bauhini | Exome (23/25=92%) | ||
| T3 | Tubular adenoma | Low grade | 33 cm distal from valvula bauhini | Exome (12/28=43%) | ||
| T4 | Tubular adenoma | Low grade | 33 cm distal from valvula bauhini | Exome (2/12=17%) | ||
| F5018 | L | c.1660C>T;p.Arg554* | Exome (32/286=11%); Multiplicom (97/1061=9%) | |||
| T1 | Tubular adenoma | Low grade | Sigmoid colon | Exome (4/16=25%) | ||
| T2 | Tubular adenoma | Low grade | Rectum | Exome (3/5=60%) | ||
| T2 | c.4348C>T;p.Arg1450* (second hit?) | Exome (4/12=33%) | ||||
| (B) Mosaic cases in leucocyte screening cohort (n=80) | ||||||
| F1252 | L | c.896_897delCT; p.Ser299Leufs*27 | Exome (7/77=9%); Multiplicom (344/3643=9%) | |||
| T1 | Tubulovillous adenoma | Low grade | Sigmoid colon | Sanger | ||
| T2 | Tubular adenoma | Low grade | Approximately 40 cm ab ano | Sanger | ||
| F1727 | L | c.2240C>G;p.Ser747* | Exome (2/26=8%); Multiplicom (113/2083=5%) | |||
| T1 | Tubulovillous adenoma | Low grade | Approximately 23 cm ab ano | Sanger | ||
| T2 | Tubulovillous adenoma | Low grade | Approximately 45 cm ab ano | Sanger | ||
| T3 | Tubulovillous adenoma | Low grade | Approximately 39 cm ab ano | Sanger | ||
| T4 | Tubulovillous adenoma | Low grade | Approximately 32 cm ab ano | Sanger | ||
L, leucocyte DNA; T, adenoma DNA.