rs730881742
Variant summary
Our verdict is Uncertain significance. Variant got 1 ACMG points: 1P and 0B. PP3
The NM_000249.4(MLH1):c.1628A>G(p.His543Arg) variant causes a missense change. The variant allele was found at a frequency of 0.0000564 in 1,613,862 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000249.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 1 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000329 AC: 5AN: 152134Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000199 AC: 5AN: 251316Hom.: 0 AF XY: 0.0000147 AC XY: 2AN XY: 135824
GnomAD4 exome AF: 0.0000588 AC: 86AN: 1461728Hom.: 0 Cov.: 30 AF XY: 0.0000605 AC XY: 44AN XY: 727190
GnomAD4 genome AF: 0.0000329 AC: 5AN: 152134Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74330
ClinVar
Submissions by phenotype
Colorectal cancer, hereditary nonpolyposis, type 2 Uncertain:2Benign:1
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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]. -
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Hereditary cancer-predisposing syndrome Uncertain:2
This missense variant replaces histidine with arginine at codon 543 of the MLH1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with breast and ovarian cancer (PMID: 34326862). This variant has been identified in 5/251316 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
The p.H543R variant (also known as c.1628A>G), located in coding exon 14 of the MLH1 gene, results from an A to G substitution at nucleotide position 1628. The histidine at codon 543 is replaced by arginine, an amino acid with highly similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -
Muir-Torré syndrome;C1333991:Colorectal cancer, hereditary nonpolyposis, type 2;C5399763:Mismatch repair cancer syndrome 1 Uncertain:1
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Lynch syndrome Uncertain:1
This missense variant replaces histidine with arginine at codon 543 of the MLH1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with MLH1-related disorders in the literature. This variant has been identified in 5/251316 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
not provided Uncertain:1
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Observed in an individual with breast and ovarian cancer (Bhai et al., 2021); This variant is associated with the following publications: (PMID: 26333163, Krishnan2021[Abstract], 12799449, 20533529, 22753075, 34326862) -
Inherited ovarian cancer (without breast cancer) Uncertain:1
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Hereditary nonpolyposis colorectal neoplasms Uncertain:1
This sequence change replaces histidine, which is basic and polar, with arginine, which is basic and polar, at codon 543 of the MLH1 protein (p.His543Arg). This variant is present in population databases (rs730881742, gnomAD 0.004%). This missense change has been observed in individual(s) with breast and ovarian cancer (PMID: 34326862). ClinVar contains an entry for this variant (Variation ID: 182526). Invitae Evidence Modeling incorporating data from in vitro experimental studies (internal data) indicates that this missense variant is not expected to disrupt MLH1 function with a negative predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Endometrial carcinoma Uncertain:1
The MLH1 p.His543Arg variant was not identified in the literature nor was it identified in the Cosmic, MutDB, Insight Colon Cancer Gene Variant Database, Zhejiang Colon Cancer Database, Mismatch Repair Genes Variant Database, and Insight Hereditary Tumors Database. The variant was identified in dbSNP (ID: rs730881742) “With Uncertain significance allele”, ClinVar (classified uncertain significance by GeneDx, Ambry Genetics, Invitae and Counsyl), Clinvitae (4x), UMD-LSDB, and in control databases in 5 of 246086 chromosomes at a frequency of 0.00002 (Genome Aggregation Database Feb 27, 2017). Breakdown of the observations by population include European Non-Finnish in 5 of 111582 chromosomes (freq: 0.00005), while not observed in the African, Other, Latino, Ashkenazi Jewish, East Asian, European Finnish, and South Asian populations. The p.His543Arg residue is not 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, 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. This variant is classified as a variant of uncertain significance. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at