rs267608026

Positions:

• chr2-47783306-G-C
• chr2-47783306-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The ENST00000234420.11(MSH6):​c.73G>C​(p.Ala25Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 14/20 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. A25S) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: MSH6 ENST00000234420.11 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0360

Genes affected

MSH6 (HGNC:7329): (mutS homolog 6) This gene encodes a member of the DNA mismatch repair MutS family. In E. coli, the MutS protein helps in the recognition of mismatched nucleotides prior to their repair. A highly conserved region of approximately 150 aa, called the Walker-A adenine nucleotide binding motif, exists in MutS homologs. The encoded protein heterodimerizes with MSH2 to form a mismatch recognition complex that functions as a bidirectional molecular switch that exchanges ADP and ATP as DNA mismatches are bound and dissociated. Mutations in this gene may be associated with hereditary nonpolyposis colon cancer, colorectal cancer, and endometrial cancer. Transcripts variants encoding different isoforms have been described. [provided by RefSeq, Jul 2013]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.22595629).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH6	NM_000179.3	c.73G>C	p.Ala25Pro	missense_variant	1/10	ENST00000234420.11	NP_000170.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH6	ENST00000234420.11	c.73G>C	p.Ala25Pro	missense_variant	1/10	1	NM_000179.3	ENSP00000234420	P4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 26, 2020

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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt MSH6 protein function. This variant has not been reported in the literature in individuals with MSH6-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces alanine with proline at codon 25 of the MSH6 protein (p.Ala25Pro). The alanine residue is weakly conserved and there is a small physicochemical difference between alanine and proline. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.067
BayesDel_addAF	Benign	-0.050	T
BayesDel_noAF	Benign	-0.31
CADD	Benign	4.2
DANN	Benign	0.87
DEOGEN2	Benign	0.22	.;T;T
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.025	N
LIST_S2	Benign	0.69	T;T;T
M_CAP	Pathogenic	0.94	D
MetaRNN	Benign	0.23	T;T;T
MetaSVM	Benign	-0.66	T
MutationAssessor	Benign	0.69	N;N;.
MutationTaster	Benign	1.0	N;N
PrimateAI	Uncertain	0.75	T
PROVEAN	Benign	0.33	N;N;.
REVEL	Benign	0.14
Sift	Benign	0.061	T;T;.
Sift4G	Benign	0.43	T;T;T
Polyphen		0.38	.;B;.
Vest4		0.18
MutPred		0.24		Gain of glycosylation at A25 (P = 0.0166);Gain of glycosylation at A25 (P = 0.0166);Gain of glycosylation at A25 (P = 0.0166);
MVP		0.62
ClinPred		0.27	T
GERP RS		0.56
Varity_R		0.11
gMVP		0.60

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs267608026; hg19: chr2-48010445; COSMIC: COSV52278996; COSMIC: COSV52278996;