NM_000179.3:c.-44G>T

Variant names:

• chr2-47783190-G-T
• rs1064793549
• NM_000179.3:c.-44G>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_000179.3(MSH6):​c.-44G>T variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,455,514 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: MSH6 NM_000179.3 5_prime_UTR_premature_start_codon_gain
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.323
• Publications: 0 publications found

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]

MSH6 Gene-Disease associations (from GenCC):

• Lynch syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, ClinGen, Orphanet
• Lynch syndrome 5

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, Genomics England PanelApp
• mismatch repair cancer syndrome 1

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• mismatch repair cancer syndrome 3

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P
• ovarian cancer

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• malignant pancreatic neoplasm

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• Muir-Torre syndrome

  Inheritance: AD Classification: MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet
• rhabdomyosarcoma

  Inheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
• breast cancer

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• prostate cancer

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• hereditary breast carcinoma

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.78).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSH6	NM_000179.3	c.-44G>T		5_prime_UTR_premature_start_codon_gain_variant	Exon 1 of 10	ENST00000234420.11	NP_000170.1
MSH6	NM_000179.3	c.-44G>T		5_prime_UTR_variant	Exon 1 of 10	ENST00000234420.11	NP_000170.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MSH6	ENST00000234420.11	c.-44G>T		5_prime_UTR_premature_start_codon_gain_variant	Exon 1 of 10	1	NM_000179.3	ENSP00000234420.5
MSH6	ENST00000234420.11	c.-44G>T		5_prime_UTR_variant	Exon 1 of 10	1	NM_000179.3	ENSP00000234420.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000417 AC: 1 AN: 239892 AF XY: 0.00000761

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000925

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1455514 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 724220

African (AFR) AF: 0.00 AC: 0 AN: 32492

American (AMR) AF: 0.00 AC: 0 AN: 44334

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25910

East Asian (EAS) AF: 0.00 AC: 0 AN: 38954

South Asian (SAS) AF: 0.00 AC: 0 AN: 85498

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52212

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5750

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1110186

Other (OTH) AF: 0.00 AC: 0 AN: 60178

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Apr 28, 2015

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is denoted MSH6 c.-44G>T, and describes a nucleotide substitution 44 base pairs upstream of the MSH6 ATG translational start site in the 5' untranslated region (UTR). The surrounding sequence, with the base that is substituted in braces, is TTTA[G/T]GAGC. This variant has not been published to our knowledge. MSH6 c.-44G>T was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. This substitution is not tolerated in evolution and it occurs at a position that is conserved in mammals. Although MSH6 c.-44G>T does not affect the usual start codon or the Kozak translational consensus sequence, it does create a new in-frame ATG start codon. Since the creation of this new start codon may or may not inhibit proper protein functioning, the clinical significance of this finding remains unclear at this time and we consider MSH6 c.-44G>T to be a variant of uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.78
CADD	Benign	11
DANN	Benign	0.46
PhyloP100		0.32
PromoterAI		0.12	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.2

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs1064793549; hg19: chr2-48010329;