rs63750027

Positions:

• chr2-47480753-A-C
• chr2-47480753-A-G
• chr2-47480753-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PM5

The NM_000251.3(MSH2):​c.2516A>C​(p.His839Pro) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H839Q) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: MSH2 NM_000251.3 missense
• Clinical Significance: Uncertain significance no assertion criteria provided U:1
• Conservation: PhyloP100: 6.52

Genes affected

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-47480754-T-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH2	NM_000251.3	c.2516A>C	p.His839Pro	missense_variant	15/16	ENST00000233146.7	NP_000242.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH2	ENST00000233146.7	c.2516A>C	p.His839Pro	missense_variant	15/16	1	NM_000251.3	ENSP00000233146	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: no assertion criteria provided

Submissions by phenotype

Malignant tumor of breast Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The MSH2 p.His839Arg variant was identified in 3 of 428 proband chromosomes (frequency: 0.007) from individuals or families with Lynch syndrome and was not identified in 400 control chromosomes from healthy individuals (Tang 2009, Wang 2006, Yuan 2004). The variant was also identified in dbSNP (ID: rs63750027) as "With Uncertain significance allele" and in ClinVar (classified as likely benign by Invitae; and as uncertain significance by InSiGHT, Ambry Genetics, GeneDx and one other submitter). The variant was not identified in UMD-LSDB. The variant was identified in control databases in 8 of 277214 chromosomes at a frequency of 0.00003 (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: Other in 1 of 6468 chromosomes (freq: 0.0002) and East Asian in 7 of 18866 chromosomes (freq: 0.0004), while the variant was not observed in the African, Latino, European, Ashkenazi Jewish, Finnish, or South Asian populations. Functional and structural analysis of the variant showed reduced protein expression as well as altered RNA structure and MutSα dimerization (Arora 2017). The p.His839 residue is conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Pathogenic	0.31	D
BayesDel_noAF	Pathogenic	0.21
CADD	Uncertain	24
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.54	D;.;.;.
Eigen	Uncertain	0.38
Eigen_PC	Uncertain	0.49
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.93	D;D;D;D
M_CAP	Benign	0.082	D
MetaRNN	Uncertain	0.58	D;D;D;D
MetaSVM	Uncertain	0.030	D
MutationAssessor	Benign	-0.67	N;.;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.55	T
PROVEAN	Uncertain	-2.8	D;D;.;D
REVEL	Pathogenic	0.68
Sift	Benign	0.067	T;T;.;T
Sift4G	Benign	0.20	T;T;.;T
Polyphen		0.90	P;.;.;D
Vest4		0.67
MutPred		0.59		Gain of catalytic residue at K838 (P = 0.2234);.;Gain of catalytic residue at K838 (P = 0.2234);Gain of catalytic residue at K838 (P = 0.2234);
MVP		0.92
MPC		0.021
ClinPred		0.92	D
GERP RS		5.9
Varity_R		0.86
gMVP		0.75

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr2-47707892;