rs63750664

chr2-47783292-C-Achr2-47783292-C-Gchr2-47783292-C-T

Variant summary

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

The NM_000179.3(MSH6):c.59C>A(p.Ala20Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000656 in 152,332 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/19 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. A20V) has been classified as Likely benign.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
• Consequence: MSH6 NM_000179.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.257

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=0.17198172).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH6	NM_000179.3	c.59C>A	p.Ala20Asp	missense_variant	1/10	ENST00000234420.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH6	ENST00000234420.11	c.59C>A	p.Ala20Asp	missense_variant	1/10	1	NM_000179.3	P4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152220 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000410 AC: 1 AN: 243766 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 133426

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000554

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 30

GnomAD4 genome AF: 0.00000656 AC: 1 AN: 152332 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74482

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000193

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ExAC AF: 0.00000829 AC: 1

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

Apr 04, 2019

The p.A20D variant (also known as c.59C>A), located in coding exon 1 of the MSH6 gene, results from a C to A substitution at nucleotide position 59. The alanine at codon 20 is replaced by aspartic acid, an amino acid with dissimilar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. In addition, the CoDP in silico tool predicts this alteration to have a minor impact on molecular function, with a score of 0.000 (Terui H et al. J. Biomed. Sci. 2013 Apr;20:25). 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	0.13
BayesDel_addAF	Benign	-0.099	T
BayesDel_noAF	Benign	-0.21
Cadd	Benign	17
Dann	Benign	0.97
Eigen	Benign	-0.76
Eigen_PC	Benign	-0.71
FATHMM_MKL	Benign	0.015	N
LIST_S2	Benign	0.56	T;T;T
M_CAP	Pathogenic	0.89	D
MetaRNN	Benign	0.17	T;T;T
MetaSVM	Benign	-0.86	T
MutationAssessor	Benign	0.55	N;N;.
MutationTaster	Benign	1.0	N;N
PrimateAI	Pathogenic	0.82	D
PROVEAN	Benign	-0.62	N;N;.
REVEL	Benign	0.19
Sift	Uncertain	0.022	D;T;.
Sift4G	Benign	0.63	T;T;T
Polyphen		0.041	.;B;.
Vest4		0.28
MVP		0.76
ClinPred		0.070	T
GERP RS		2.1
RBP_binding_hub_radar		0.97
RBP_regulation_power_radar		2.1
Varity_R		0.19
gMVP		0.63

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: rs63750664; hg19: chr2-48010431;