Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PS1_ModeratePM1PM2PM5PP3_Strong
The NM_000251.3(MSH2):c.2275G>C(p.Gly759Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 13/21 in silico tools predict a damaging outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G759E) has been classified as Likely benign.
MSH2 (HGNC:7325): (mutS homolog 2) This locus is frequently mutated in hereditary nonpolyposis colon cancer (HNPCC). When cloned, it was discovered to be a human homolog of the E. coli mismatch repair gene mutS, consistent with the characteristic alterations in microsatellite sequences (RER+ phenotype) found in HNPCC. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Apr 2012]
Verdict is Pathogenic. Variant got 12 ACMG points.
PS1
Transcript NM_000251.3 (MSH2) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar as 1307609
PM1
In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 8 benign, 16 uncertain in NM_000251.3
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr2-47478337-G-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1005173.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=2}.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.992