rs727503299

Positions:

• chr12-110915765-C-A
• chr12-110915765-C-G
• chr12-110915765-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_000432.4(MYL2):​c.119G>T​(p.Arg40Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: MYL2 NM_000432.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.57

Genes affected

MYL2 (HGNC:7583): (myosin light chain 2) This gene encodes a major sarcomeric protein in mammalian striated muscle. The encoded protein plays a role in embryonic heart muscle structure and function, while phosphorylation of the encoded protein is involved in cardiac myosin cycling kinetics, torsion and function in adults. Mutations in this gene are associated with hypertrophic cardiomyopathy 10 and infant-onset myopathy. [provided by RefSeq, May 2022]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a domain EF-hand 1 (size 35) in uniprot entity MLRV_HUMAN there are 7 pathogenic changes around while only 0 benign (100%) in NM_000432.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.909

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYL2	NM_000432.4	c.119G>T	p.Arg40Met	missense_variant	3/7	ENST00000228841.15	NP_000423.2
MYL2	NM_001406916.1	c.62G>T	p.Arg21Met	missense_variant	3/7		NP_001393845.1
MYL2	NM_001406745.1	c.94-1441G>T		intron_variant			NP_001393674.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYL2	ENST00000228841.15	c.119G>T	p.Arg40Met	missense_variant	3/7	1	NM_000432.4	ENSP00000228841.8
MYL2	ENST00000663220.1	c.62G>T	p.Arg21Met	missense_variant	3/7			ENSP00000499568.1
MYL2	ENST00000548438.1	c.94-1441G>T		intron_variant		3		ENSP00000447154.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

May 17, 2013

- -

Hypertrophic cardiomyopathy 10 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 01, 2023

This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with methionine, which is neutral and non-polar, at codon 40 of the MYL2 protein (p.Arg40Met). This variant has not been reported in the literature in individuals affected with MYL2-related conditions. ClinVar contains an entry for this variant (Variation ID: 178974). An algorithm developed specifically for the MYL2 gene suggests that this missense change is likely to be deleterious (PMID: 21310275). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
CardioboostCm	Uncertain	0.75
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.16
CADD	Pathogenic	30
DANN	Benign	0.97
DEOGEN2	Pathogenic	0.83	D
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D
M_CAP	Uncertain	0.24	D
MetaRNN	Pathogenic	0.91	D
MetaSVM	Uncertain	0.32	D
MutationAssessor	Pathogenic	3.2	M
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-5.5	D
REVEL	Uncertain	0.63
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.78
MutPred		0.58		Gain of catalytic residue at N39 (P = 0.0179);
MVP		0.91
MPC		1.3
ClinPred		1.0	D
GERP RS		5.1
Varity_R		0.87
gMVP		0.87

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs727503299; hg19: chr12-111353569;