Table 3.
Germline LGRs identified in Slovakian HNPCC families.
| Family code | HNPCC criteria | Tumor localization (age at diagnosis) |
Gene | Deleted or duplicated exons (systematic nomenclature) |
5' deletion | MSI | IHC | LOH |
|---|---|---|---|---|---|---|---|---|
| SK-14 | AC-I | ascendens + sigmoid colon (27) | MSH2 | del1-7 (c.1-?_1276+?del) | 15 kb | MSI-H | * | partial |
| SK-20 | AC-II | sigmoid colon (36) | MSH2 | dup5-6 (c.793-?_1076+?dup) | n.a. | MSI-H | MLH1+, MSH2- | partial |
| SK-21 | BG | cecum (27) | MSH2 | del1-3 (c.1-?_645+?del) | 15 kb and 27 kb | MSI-H | MLH1+, MSH2- | none |
| SK-22 | AC-I | sigmoid colon (36) | MLH1 | del5-6 (c.381-?_545+?del) | n.a. | MSI-H | MLH1-, MSH2+ | partial |
| SK-23 | AC-I | cecum + ascendens colon (53) | MSH2 | del1 (c.1-?_211+?del) | - | MSI-L | * | none |
| SK-25 | AC-I | cecum (42) | MSH2 | del1-7 (c.1-?_1276+?del) | 15 kb | # | # | |
| SK-28 | BG | ascendens colon + rectum (48) | MSH2 | del1-3 (c.1-?_645+?del) | n.d. | MSI-H | * | n.i. |
Fulfillment of HNPCC criteria: AC-I, AC-II, Amsterdam criteria I, II; BG, Bethesda guidelines. Systematic nomenclature: According to the recommendations of the Human Genome Variant Society using reference sequences NM_000249.2 (MLH1) and NM_000251.1 (MSH2). 5' deletion: the probes detecting regions located 15 or 27 kb before MSH2 localized in the TACSTD1 gene; n.a., not applicable; - no reduction of the signal at any of the TACSTD1 probes, n.d., not determined; MSI, microsatellite instability analysis: MSI-H, high level of MSI; MSI-L, low level of MSI; IHC, immunohistochemical analysis, +, a positive staining, -, a negative staining, * staining failed due to fixation problem; #, no FFPE tissue available for analysis; LOH, loss of heterozygosity, n.i. not informative in any LOH marker