2-47783481-C-T

Position:

• chr2-47783481-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_000179.3(MSH6):​c.248C>T​(p.Ala83Val) 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. 13/20 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. A83D) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: MSH6 NM_000179.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.592

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 2 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 16 uncertain in NM_000179.3
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.18154085).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH6	NM_000179.3	c.248C>T	p.Ala83Val	missense_variant	1/10	ENST00000234420.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH6	ENST00000234420.11	c.248C>T	p.Ala83Val	missense_variant	1/10	1	NM_000179.3	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1279656 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 621124

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 13, 2019

The p.A83V variant (also known as c.248C>T), located in coding exon 1 of the MSH6 gene, results from a C to T substitution at nucleotide position 248. The alanine at codon 83 is replaced by valine, an amino acid with 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. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.093
BayesDel_addAF	Benign	-0.038	T
BayesDel_noAF	Benign	-0.29
CADD	Benign	17
DANN	Uncertain	0.99
DEOGEN2	Benign	0.25	T;T
Eigen	Benign	-1.0
Eigen_PC	Benign	-0.99
FATHMM_MKL	Benign	0.11	N
LIST_S2	Benign	0.71	T;T
M_CAP	Pathogenic	0.75	D
MetaRNN	Benign	0.18	T;T
MetaSVM	Benign	-0.80	T
MutationAssessor	Benign	0.55	N;.
MutationTaster	Benign	1.0	N;N
PrimateAI	Pathogenic	0.79	T
PROVEAN	Benign	-0.34	N;.
REVEL	Benign	0.14
Sift	Benign	0.076	T;.
Sift4G	Benign	0.11	T;T
Polyphen		0.030	B;.
Vest4		0.27
MutPred		0.22		Loss of glycosylation at P82 (P = 0.0613);.;
MVP		0.64
ClinPred		0.13	T
GERP RS		2.0
Varity_R		0.034
gMVP		0.26

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs876661197; hg19: chr2-48010620;