2-47800156-A-G
Variant summary
Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBP6
The NM_000179.3(MSH6):c.2173A>G(p.Ile725Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000812 in 1,614,098 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I725M) has been classified as Uncertain significance.
Frequency
Consequence
NM_000179.3 missense
Scores
Clinical Significance
Conservation
Publications
- intellectual developmental disorder with dysmorphic facies and behavioral abnormalitiesInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
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ACMG classification
Our verdict: Likely_benign. The variant received -5 ACMG points.
Variant Effect in Transcripts
ACMG analysis was done for transcript: NM_000179.3. You can select a different transcript below to see updated ACMG assignments.
RefSeq Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| MSH6 | NM_000179.3 | MANE Select | c.2173A>G | p.Ile725Val | missense | Exon 4 of 10 | NP_000170.1 | ||
| MSH6 | NM_001406795.1 | c.2269A>G | p.Ile757Val | missense | Exon 5 of 11 | NP_001393724.1 | |||
| MSH6 | NM_001406813.1 | c.2179A>G | p.Ile727Val | missense | Exon 4 of 10 | NP_001393742.1 |
Ensembl Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| MSH6 | ENST00000234420.11 | TSL:1 MANE Select | c.2173A>G | p.Ile725Val | missense | Exon 4 of 10 | ENSP00000234420.5 | ||
| MSH6 | ENST00000445503.5 | TSL:1 | n.*1520A>G | non_coding_transcript_exon | Exon 3 of 9 | ENSP00000405294.1 | |||
| MSH6 | ENST00000445503.5 | TSL:1 | n.*1520A>G | 3_prime_UTR | Exon 3 of 9 | ENSP00000405294.1 |
Frequencies
GnomAD3 genomes AF: 0.0000526 AC: 8AN: 152230Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.000104 AC: 26AN: 250960 AF XY: 0.000111 show subpopulations
GnomAD4 exome AF: 0.0000841 AC: 123AN: 1461868Hom.: 0 Cov.: 34 AF XY: 0.0000935 AC XY: 68AN XY: 727236 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000526 AC: 8AN: 152230Hom.: 0 Cov.: 32 AF XY: 0.0000538 AC XY: 4AN XY: 74358 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:2Benign:1
This variant is associated with the following publications: (PMID: 23621914, 25186627)
The MSH6 p.Ile725Val variant was not identified in the literature. The variant was identified in dbSNP (ID: rs148898662) as "With Uncertain significance allele", ClinVar (classified as likely benign by Ambry Genetics; as uncertain significance by GeneDx and Invitae), and in UMD-LSDB (1x as unclassified variant). The variant was identified in control databases in 28 of 276672 chromosomes at a frequency of 0.0001 (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: Latino in 2 of 34406 chromosomes (freq: 0.00006), European in 12 of 126200 chromosomes (freq: 0.0001), and South Asian in 14 of 30782 chromosomes (freq: 0.0005); the variant was not observed in the African, “Other”, Ashkenazi Jewish, East Asian, or Finnish, populations. The p.Ile725 residue is not conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood of impact to the protein; however, this information is not predictive enough to rule out 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.
Lynch syndrome 5 Benign:2
This variant is considered likely benign. This variant is strongly associated with less severe personal and family histories of cancer, typical for individuals without pathogenic variants in this gene [PMID: 27363726].
not specified Benign:2
Variant summary: MSH6 c.2173A>G (p.Ile725Val) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.0001 in 250960 control chromosomes, predominantly at a frequency of 0.00046 within the South Asian subpopulation in the gnomAD database. The observed variant frequency within South Asian control individuals in the gnomAD database is approximately 3-fold of the estimated maximal expected allele frequency for a pathogenic variant in MSH6 causing Hereditary Nonpolyposis Colorectal Cancer phenotype (0.00014), strongly suggesting that the variant is a benign polymorphism found primarily in populations of South Asian origin. c.2173A>G has been reported in the literature in individuals affected with unspecified cancer or having undertaken cancer gene testing, without strong evidence for causality (examples, Tung_2014, Zhang_2015, Carnevali_2021). These report(s) do not provide unequivocal conclusions about association of the variant with Hereditary Nonpolyposis Colorectal Cancer. This variant has also been reported in both case and control cohorts from a large case-control study of Breast cancers (Dorling_2021). Co-occurrences with other pathogenic variant(s) have been reported (MSH6 c.(260+1_261_1)_(457+1_458-1)del p.(Ser87Argfs*19)), providing supporting evidence for a benign role (Carnevali_2021). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 34519692, 33471991, 23621914, 25186627, 26580448). Seven submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 (VUS, n=2; Likely benign, n=5). Based on the evidence outlined above, the variant was classified as likely benign.
Hereditary cancer-predisposing syndrome Benign:2
This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.
Breast and/or ovarian cancer Uncertain:1
Hereditary nonpolyposis colorectal neoplasms Benign:1
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at