chr3-46859510-A-G

Variant names:

• chr3-46859510-A-G
• rs202141423
• NM_000258.3:c.446T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PM5 PP2 PP3 PP5

The NM_000258.3(MYL3):​c.446T>C​(p.Met149Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,614,158 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M149I) has been classified as Likely pathogenic. The gene MYL3 is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: MYL3 NM_000258.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:4
• Conservation: PhyloP100: 9.32
• Publications: 1 publications found

Genes affected

MYL3 (HGNC:7584): (myosin light chain 3) MYL3 encodes myosin light chain 3, an alkali light chain also referred to in the literature as both the ventricular isoform and the slow skeletal muscle isoform. Mutations in MYL3 have been identified as a cause of mid-left ventricular chamber type hypertrophic cardiomyopathy. [provided by RefSeq, Jul 2008]

MYL3 Gene-Disease associations (from GenCC):

• hypertrophic cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• hypertrophic cardiomyopathy 8

  Inheritance: AD, SD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• dilated cardiomyopathy

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Specifications for MYL3 are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 17 uncertain in NM_000258.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-46859509-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 180442.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 4 curated pathogenic missense variants (we use a threshold of 10). The gene has 1 curated benign missense variants. Gene score misZ: 0.75572 (below the threshold of 3.09). Trascript score misZ: 1.3243 (below the threshold of 3.09). GenCC associations: The gene is linked to hypertrophic cardiomyopathy, hypertrophic cardiomyopathy 8, arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.82
• PP5: Variant 3-46859510-A-G is Pathogenic according to our data. Variant chr3-46859510-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 43123.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000258.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYL3	NM_000258.3	MANE Select	c.446T>C	p.Met149Thr	missense	Exon 4 of 7	NP_000249.1	P08590
	MYL3	NM_001406937.1		c.446T>C	p.Met149Thr	missense	Exon 4 of 6	NP_001393866.1	P08590
	MYL3	NM_001406938.1		c.446T>C	p.Met149Thr	missense	Exon 6 of 9	NP_001393867.1	P08590

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYL3	ENST00000292327.6	TSL:1 MANE Select	c.446T>C	p.Met149Thr	missense	Exon 4 of 7	ENSP00000292327.4	P08590
	MYL3	ENST00000395869.5	TSL:1	c.446T>C	p.Met149Thr	missense	Exon 4 of 6	ENSP00000379210.1	P08590
	MYL3	ENST00000713934.1		c.578T>C	p.Met193Thr	missense	Exon 4 of 7	ENSP00000519231.1	A0AAQ5BH63

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152158 Hom.: 0 Cov.: 32

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

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251474 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461882 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727240

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112006

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152276 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74458

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41560

American (AMR) AF: 0.00 AC: 0 AN: 15298

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3466

East Asian (EAS) AF: 0.000193 AC: 1 AN: 5174

South Asian (SAS) AF: 0.00 AC: 0 AN: 4822

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2110

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
1	1	-	Hypertrophic cardiomyopathy 8 (2)
-	2	-	not specified (2)
1	-	-	Cardiovascular phenotype (1)
-	1	-	Hypertrophic cardiomyopathy (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
CardioboostCm	Uncertain	0.89
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.28
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.69	D
Eigen	Benign	0.037
Eigen_PC	Benign	0.20
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Benign	0.78	T
M_CAP	Benign	0.077	D
MetaRNN	Pathogenic	0.82	D
MetaSVM	Benign	-0.56	T
MutationAssessor	Benign	1.9	L
PhyloP100		9.3
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-5.5	D
REVEL	Pathogenic	0.67
Sift	Benign	0.038	D
Sift4G	Benign	0.85	T
Polyphen		0.18	B
Vest4		0.99
MVP		0.94
MPC		1.0
ClinPred		0.99	D
GERP RS		4.3
Varity_R		0.84
gMVP		0.69
Mutation Taster		=12/88	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs202141423; hg19: chr3-46901000;