3-37050592-A-T
Variant summary
Our verdict is Uncertain significance. Variant got 0 ACMG points: 1P and 1B. PP3BP6
The NM_000249.4(MLH1):c.2210A>T(p.Asp737Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000041 in 1,461,860 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 0 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 33
GnomAD3 exomes AF: 0.00000398 AC: 1AN: 251274Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 135794
GnomAD4 exome AF: 0.00000410 AC: 6AN: 1461860Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2AN XY: 727236
GnomAD4 genome Cov.: 33
ClinVar
Submissions by phenotype
not provided Uncertain:2
Not observed at a significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Published functional studies demonstrate no damaging effect: shown to be non-pathogenic via oligonucleotide-directed mutation screening (PMID: 31784484); Observed in trans with a MLH1 pathogenic variant in an individual meeting Amsterdam criteria; however, the variant was shown to not segregate with disease (PMID: 15849733, 16341550); This variant is associated with the following publications: (PMID: 9419403, 22949387, 18383312, 15849733, 21404117, 16341550, 23760103, 23435383, 20533529, 22753075, 12799449, 31784484) -
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Hereditary cancer-predisposing syndrome Benign:2
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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. -
Colorectal cancer, hereditary nonpolyposis, type 2 Uncertain:1
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MLH1-related disorder Uncertain:1
The MLH1 c.2210A>T variant is predicted to result in the amino acid substitution p.Asp737Val. This variant was reported, along with additional MLH1 variants, in individuals with non-polyposis colorectal cancer (Pagenstecher et al. 2006. PubMed ID: 16341550; Mangold et al. 2005. PubMed ID: 15849733). The significance of these reports is unclear given the uncertainty of the clinical significance of the additional variants and/or the variant phasing. This variant is reported in 0.00088% of alleles in individuals of European (Non-Finnish) descent in gnomAD. In ClinVar, this variant has conflicting interpretations of likely benign and uncertain significance (https://www.ncbi.nlm.nih.gov/clinvar/variation/90090/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Hereditary nonpolyposis colorectal neoplasms Uncertain:1
This sequence change replaces aspartic acid, which is acidic and polar, with valine, which is neutral and non-polar, at codon 737 of the MLH1 protein (p.Asp737Val). This variant is present in population databases (rs267607885, gnomAD 0.0009%). This missense change has been observed to co-occur in individuals with a different variant in MLH1 that has been determined to be pathogenic (PMID: 16341550), but the significance of this finding is unclear. ClinVar contains an entry for this variant (Variation ID: 90090). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on MLH1 protein function. Experimental studies have shown that this missense change does not substantially affect MLH1 function (PMID: 31784484). RNA analysis performed to evaluate the impact of this missense change on mRNA splicing indicates it does not significantly alter splicing (internal data). 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. -
Lynch syndrome Benign:1
This missense variant replaces aspartic acid with valine at codon 737 of the MLH1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in a HNPCC family who also had a pathogenic splice mutation in the same gene, in which the c.2210A>T variant is stated to not segregate with disease (PMID: 15849733, 16341550, 21404117). This variant has been identified in 1/251274 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at