rs267607824
Variant summary
Our verdict is Benign. Variant got -17 ACMG points: 0P and 17B. BP4_StrongBP6_Very_StrongBP7BS1
The NM_000249.4(MLH1):c.1128T>C(p.Asp376Asp) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000353 in 1,613,086 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★★).
Frequency
Consequence
NM_000249.4 synonymous
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Benign. Variant got -17 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000462 AC: 7AN: 151360Hom.: 0 Cov.: 31
GnomAD3 exomes AF: 0.0000676 AC: 17AN: 251440Hom.: 0 AF XY: 0.0000589 AC XY: 8AN XY: 135896
GnomAD4 exome AF: 0.0000342 AC: 50AN: 1461726Hom.: 0 Cov.: 34 AF XY: 0.0000330 AC XY: 24AN XY: 727164
GnomAD4 genome AF: 0.0000462 AC: 7AN: 151360Hom.: 0 Cov.: 31 AF XY: 0.0000406 AC XY: 3AN XY: 73828
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Benign:3
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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. -
not specified Benign:2
This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Variant summary: MLH1 c.1128T>C alters a non-conserved nucleotide resulting in a synonymous change. 5/5 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The observed variant frequency within East Asian control individuals in the gnomAD database is approximately 1.55 fold of the estimated maximal expected allele frequency for a pathogenic variant in MLH1 causing Lynch Syndrome phenotype (0.00071), strongly suggesting that the variant is a benign polymorphism found primarily in populations of East Asian origin. c.1128T>C has been reported in the literature in individuals affected with Lynch Syndrome, however 9 out of the reported 18 families with c.1128T>C (Asp376) also had pathogenic mutations in MLH1, MSH2 or MSH6 (Shin_2004), strongly supporting the benign nature of this variant. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Five clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as benign/likely benign. Based on the evidence outlined above, the variant was classified as benign. -
Colorectal cancer, hereditary nonpolyposis, type 2 Benign:2
This variant is considered benign. This variant is a silent/synonymous amino acid change and it is not expected to impact splicing. -
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Lynch syndrome Benign:2
MAF >1% -
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not provided Benign:2
MLH1, EXON 12, c.1128T>C, p.Asp376=, Heterozygous, Likely benign The MLH1 p.Asp376= variant was identified in 18 of 282 proband chromosomes (frequency: 0.06) from individuals or families with Lynch syndrome and was present in 12 of 368 control chromosomes (frequency: 0.03) from healthy individuals (Shin 2004). The variant was also identified in the following databases: dbSNP (ID: rs267607824) as "With Likely benign allele", ClinVar (3x likely benign, 3x benign including review by expert panel InSiGHT), Clinvitae, Mismatch Repair Genes Variant Database, and the Insight Hereditary Tumors Database (1x, not pathogenic). The variant was not identified in GeneInsight-COGR, Cosmic, MutDB, UMD-LSDB, or the Zhejiang Colon Cancer Database. The variant was identified in control databases in 20 of 276984 chromosomes at a frequency of 0.00007 (Genome Aggregation Database Feb 27, 2017). Breakdown of the observations by population include East Asian in 20 of 18854 chromosomes (freq: 0.001), while the variant was not observed in the African, Other, Latino, European, Ashkenazi Jewish, Finnish, and South Asian populations. A study by Shin 2004 found no statistically significant difference in frequency between Lynch syndrome patients and controls for this variant, and listed it as a polymorphism. The p.Asp376= variant is not expected to have clinical significance because it does not result in a change of amino acid and is not located in a known consensus splice site. In addition, in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) 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 although we would lean towards a more benign role for this variant. This variant is classified as likely benign. -
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Hereditary nonpolyposis colorectal neoplasms Benign:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at