rs754879198
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate
The NM_000179.3(MSH6):c.958C>A(p.Pro320Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,614,036 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P320L) 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: Uncertain_significance. The variant received 0 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152166Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000796 AC: 2AN: 251328 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 6.84e-7 AC: 1AN: 1461870Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1AN XY: 727234 show subpopulations
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152166Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74340 show subpopulations
ClinVar
Submissions by phenotype
not provided Uncertain:1
The MSH6 c.958C>A; p.Pro320Thr variant (rs754879198), to our knowledge, is not reported in the medical literature but is reported in ClinVar (Variation ID: 1049063). This variant is only observed on two alleles in the Genome Aggregation Database, indicating it is not a common polymorphism. Computational analyses predict that this variant is neutral (REVEL: 0.11). Due to limited information, the clinical significance of this variant is uncertain at this time. -
Hereditary cancer-predisposing syndrome Uncertain:1
The p.P320T variant (also known as c.958C>A), located in coding exon 4 of the MSH6 gene, results from a C to A substitution at nucleotide position 958. The proline at codon 320 is replaced by threonine, an amino acid with highly similar properties. 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. Based on the available evidence, the clinical significance of this variant remains unclear. -
Endometrial carcinoma Benign:1
The MSH6 p.Pro320Thr variant was found to have no impact on MSH6 using a bioinformatics tool (CoDP (Combination of the Different Properties) that integrated the prediction results of MAPP, PolyPhen-2, SIFT and 2 other structural properties (Terui 2013). The variant was identified in the following databases: dbSNP (ID: rs754879198) “With Uncertain significance allele”, ClinVar (classified as uncertain significance by Invitae), and in control databases in 1 of 246084 chromosomes at a frequency of 0.000004 (Genome Aggregation Consortium Feb 27, 2017); it was observed in the European Non-Finnish population in 1 of 111572 chromosomes (freq: 0.000009) and not in other populations. The variant was not identified in the following databases: COGR, Cosmic, MutDB, UMD-LSDB, Insight Colon Cancer, Zhejiang Colon Cancer, Mismatch Repair Genes, and the Insight Hereditary Tumors Database. The variant was also identified by our laboratory in 1 individual with breast and endometrial disease, co-occurring with a pathogenic MSH6 variant (c.741delA, p.Lys247AsnfsX32), increasing the likelihood that the p.Pro320Thr variant does not have clinical significance. The p.Pro320 residue is not conserved in mammals and four out of five computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood Thr impacts 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, 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at