16-15759659-C-T

Position:

• chr16-15759659-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP2 PP3

The NM_002474.3(MYH11):​c.1318G>A​(p.Val440Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: MYH11 NM_002474.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 2.16

Genes affected

MYH11 (HGNC:7569): (myosin heavy chain 11) The protein encoded by this gene is a smooth muscle myosin belonging to the myosin heavy chain family. The gene product is a subunit of a hexameric protein that consists of two heavy chain subunits and two pairs of non-identical light chain subunits. It functions as a major contractile protein, converting chemical energy into mechanical energy through the hydrolysis of ATP. A chromosomal rearrangement involving this gene is associated with acute myeloid leukemia of the M4Eo subtype. Mutations in this gene are associated with visceral myopathy, megacystis-microcolon-intestinal hypoperistalsis syndrome 2, and familial thoracic aortic aneurysm 4. [provided by RefSeq, May 2022]

LOC124903650 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), MYH11. . Gene score misZ 1.4389 (greater than the threshold 3.09). Trascript score misZ 3.4142 (greater than threshold 3.09). GenCC has associacion of gene with aortic aneurysm, familial thoracic 4, visceral myopathy 2, familial thoracic aortic aneurysm and aortic dissection, megacystis-microcolon-intestinal hypoperistalsis syndrome 2, megacystis-microcolon-intestinal hypoperistalsis syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.809

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYH11	NM_002474.3	c.1318G>A	p.Val440Met	missense_variant	12/41	ENST00000300036.6	NP_002465.1
MYH11	NM_001040113.2	c.1339G>A	p.Val447Met	missense_variant	13/43	ENST00000452625.7	NP_001035202.1
LOC124903650	XR_007065004.1	n.632C>T		non_coding_transcript_exon_variant	2/2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYH11	ENST00000300036.6	c.1318G>A	p.Val440Met	missense_variant	12/41	1	NM_002474.3	ENSP00000300036	P3
MYH11	ENST00000452625.7	c.1339G>A	p.Val447Met	missense_variant	13/43	1	NM_001040113.2	ENSP00000407821

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461894 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727248

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 31

Bravo AF: 0.0000113

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Nov 06, 2022	This missense variant replaces valine with methionine at codon 447 of the MYH11 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with MYH11-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Feb 24, 2023	This missense variant replaces valine with methionine at codon 447 of the MYH11 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with MYH11-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Aortic aneurysm, familial thoracic 4 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 27, 2021

This sequence change replaces valine with methionine at codon 447 of the MYH11 protein (p.Val447Met). The valine residue is highly conserved and there is a small physicochemical difference between valine and methionine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with MYH11-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C15"). 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. -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 05, 2013

There is insufficient or conflicting evidence for classification of this alteration. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.83
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.11
CADD	Uncertain	26
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.68	.;.;.;D
Eigen	Uncertain	0.62
Eigen_PC	Uncertain	0.57
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Uncertain	0.97	D;D;D;D
M_CAP	Uncertain	0.11	D
MetaRNN	Pathogenic	0.81	D;D;D;D
MetaSVM	Uncertain	0.26	D
MutationAssessor	Benign	1.2	.;.;L;L
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Pathogenic	0.82	D
PROVEAN	Benign	-1.7	N;N;.;N
REVEL	Uncertain	0.55
Sift	Uncertain	0.0010	D;D;.;D
Sift4G	Uncertain	0.0020	D;D;D;D
Polyphen		1.0	.;.;.;D
Vest4		0.64
MutPred		0.65		.;.;Gain of catalytic residue at V440 (P = 0.0146);Gain of catalytic residue at V440 (P = 0.0146);
MVP		0.84
MPC		1.8
ClinPred		0.95	D
GERP RS		5.8
Varity_R		0.37
gMVP		0.89

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: rs886038900; hg19: chr16-15853516; COSMIC: COSV55547028;