rs104894369

Positions:

• chr12-110914287-C-A
• chr12-110914287-C-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1 PM2 PM5 PP3_Moderate PP5_Very_Strong

The NM_000432.4(MYL2):​c.173G>T​(p.Arg58Leu) 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R58Q) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYL2 NM_000432.4 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.50

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 Pathogenic. Variant got 16 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
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr12-110914287-C-T is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.873
• PP5: Variant 12-110914287-C-A is Pathogenic according to our data. Variant chr12-110914287-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 532778.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYL2	NM_000432.4	c.173G>T	p.Arg58Leu	missense_variant	4/7	ENST00000228841.15	NP_000423.2
MYL2	NM_001406745.1	c.131G>T	p.Arg44Leu	missense_variant	3/6		NP_001393674.1
MYL2	NM_001406916.1	c.116G>T	p.Arg39Leu	missense_variant	4/7		NP_001393845.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYL2	ENST00000228841.15	c.173G>T	p.Arg58Leu	missense_variant	4/7	1	NM_000432.4	ENSP00000228841	P1
MYL2	ENST00000548438.1	c.131G>T	p.Arg44Leu	missense_variant	3/6	3		ENSP00000447154
MYL2	ENST00000663220.1	c.116G>T	p.Arg39Leu	missense_variant	4/7			ENSP00000499568
MYL2	ENST00000549029.1	n.4G>T		non_coding_transcript_exon_variant	1/2	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Nov 01, 2023	MYL2: PM2, PM5, PS4:Moderate -
Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Sep 19, 2019	Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Reported in ClinVar as a likely pathogenic variant (ClinVar Variant ID# 532778; Landrum et al., 2016); This variant is associated with the following publications: (PMID: 24793961, 26914223) -

Hypertrophic cardiomyopathy 10 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 13, 2023

This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 58 of the MYL2 protein (p.Arg58Leu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with hypertrophic cardiomyopathy (PMID: 26914223; Invitae). ClinVar contains an entry for this variant (Variation ID: 532778). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. This variant disrupts the p.Arg58 amino acid residue in MYL2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9535554, 12404107, 14594949, 19150977, 20855589). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.77
CardioboostCm	Pathogenic	0.91
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.27
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.73	D;.
Eigen	Uncertain	0.44
Eigen_PC	Uncertain	0.50
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Pathogenic	0.98	D;D
M_CAP	Pathogenic	0.47	D
MetaRNN	Pathogenic	0.87	D;D
MetaSVM	Benign	-0.30	T
MutationAssessor	Benign	0.66	N;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.85	D
PROVEAN	Uncertain	-4.3	D;D
REVEL	Uncertain	0.60
Sift	Uncertain	0.0020	D;D
Sift4G	Uncertain	0.0040	D;D
Polyphen		1.0	D;.
Vest4		0.91
MutPred		0.52		Gain of catalytic residue at A55 (P = 6e-04);.;
MVP		0.91
MPC		0.75
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.94
gMVP		0.89

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs104894369; hg19: chr12-111352091;