2-47798716-A-T
Variant summary
Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBS1_Supporting
The NM_000179.3(MSH6):c.733A>T(p.Ile245Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000155 in 1,614,080 control chromosomes in the GnomAD database, including 1 homozygotes. 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. I245V) has been classified as Likely benign.
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.733A>T | p.Ile245Leu | missense | Exon 4 of 10 | NP_000170.1 | ||
| MSH6 | NM_001406795.1 | c.829A>T | p.Ile277Leu | missense | Exon 5 of 11 | NP_001393724.1 | |||
| MSH6 | NM_001406813.1 | c.739A>T | p.Ile247Leu | 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.733A>T | p.Ile245Leu | missense | Exon 4 of 10 | ENSP00000234420.5 | ||
| MSH6 | ENST00000445503.5 | TSL:1 | n.*80A>T | non_coding_transcript_exon | Exon 3 of 9 | ENSP00000405294.1 | |||
| MSH6 | ENST00000445503.5 | TSL:1 | n.*80A>T | 3_prime_UTR | Exon 3 of 9 | ENSP00000405294.1 |
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152218Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251164 AF XY: 0.00000737 show subpopulations
GnomAD4 exome AF: 0.0000150 AC: 22AN: 1461862Hom.: 1 Cov.: 34 AF XY: 0.00000963 AC XY: 7AN XY: 727234 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152218Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74376 show subpopulations
ClinVar
Submissions by phenotype
not provided Uncertain:4
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 23621914, 24123366, 23729658, 28874130, 30733081, 21437237, 31841383)
Lynch syndrome 5 Uncertain:2
This sequence change replaces isoleucine with leucine at codon 245 of the MSH6 protein (p.Ile245Leu). The isoleucine residue is weakly conserved and there is a small physicochemical difference between isoleucine and leucine. This variant is present in population databases (rs762168786, ExAC 0.002%). This variant has been reported in an individual affected with colorectal cancer in the Universal Mutation Database (PMID: 23729658) and in a family with suspected Lynch syndrome (PMID: 28874130). ClinVar has 5 entries for this mutation and all are listed as variant of unknown significance. An algorithm developed specifically for the MSH6 gene suggests that this missense change is likely to be tolerated (PMID: 23621914). However, this prediction has not been confirmed by published functional studies and its clinical significance is uncertain. 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.
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance.
Hereditary cancer-predisposing syndrome Uncertain:1Benign:1
The p.I245L variant (also known as c.733A>T), located in coding exon 4 of the MSH6 gene, results from an A to T substitution at nucleotide position 733. The isoleucine at codon 245 is replaced by leucine, an amino acid with highly similar properties. This alteration has been reported in one family from Uruguay who met Amsterdam II criteria and/or Bethesda guidelines (Rossi BM et al. BMC Cancer, 2017 Sep;17:623). This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.
not specified Uncertain:1
Variant summary: The MSH6 c.733A>T (p.Ile245Leu) variant involves the alteration of a non-conserved nucleotide. 5/5 in silico tools used predict a benign outcome for this variant and the variant is located outside of any known functional domain, however no functional studies confirming these predictions have been published at the time of evaluation. This variant was found in 1/215148 control chromosomes at a frequency of 0.0000046, which does not exceed the maximal expected allele frequency of a pathogenic MSH6 variant (0.0001421). This variant has been reported in at least one LS patient without strong evidence supporting causality (Rossi_2017). In addition, multiple clinical diagnostic laboratories classified this variant as uncertain significance. Taken together, this variant is classified as VUS.
Hereditary nonpolyposis colorectal neoplasms Benign:1
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at