NM_000432.4:c.119G>C

Variant names:

• chr12-110915765-C-G
• rs727503299
• NM_000432.4:c.119G>C

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>C​(p.Arg40Thr) 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, 0.913

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYL2	NM_000432.4	c.119G>C	p.Arg40Thr	missense_variant	Exon 3 of 7	ENST00000228841.15	NP_000423.2
MYL2	NM_001406916.1	c.62G>C	p.Arg21Thr	missense_variant	Exon 3 of 7		NP_001393845.1
MYL2	NM_001406745.1	c.94-1441G>C		intron_variant	Intron 2 of 5		NP_001393674.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYL2	ENST00000228841.15	c.119G>C	p.Arg40Thr	missense_variant	Exon 3 of 7	1	NM_000432.4	ENSP00000228841.8
MYL2	ENST00000663220.1	c.62G>C	p.Arg21Thr	missense_variant	Exon 3 of 7			ENSP00000499568.1
MYL2	ENST00000548438.1	c.94-1441G>C		intron_variant	Intron 2 of 5	3		ENSP00000447154.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypertrophic cardiomyopathy 10 Uncertain:1

Jul 19, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with threonine, which is neutral and polar, at codon 40 of the MYL2 protein (p.Arg40Thr). 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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 1034666). This missense change has been observed in individual(s) with clinical features of dilated cardiomyopathy (Invitae). This variant is not present in population databases (gnomAD no frequency). -

Hypertrophic cardiomyopathy Uncertain:1

Aug 06, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
CardioboostCm	Uncertain	0.70
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.060
CADD	Pathogenic	29
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.83	D
Eigen	Pathogenic	0.91
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Uncertain	0.28	D
MetaRNN	Pathogenic	0.91	D
MetaSVM	Uncertain	0.39	D
MutationAssessor	Pathogenic	3.0	M
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-5.6	D
REVEL	Uncertain	0.59
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0040	D
Polyphen		0.98	D
Vest4		0.83
MutPred		0.50		Gain of catalytic residue at F43 (P = 0.0075);
MVP		0.89
MPC		1.5
ClinPred		1.0	D
GERP RS		5.1
Varity_R		0.93
gMVP		0.89

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;