chr12-110919113-T-G

Variant names:

• chr12-110919113-T-G
• rs397516410
• NM_000432.4:c.84A>C

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1 PM2 PP2 PP3_Moderate

The NM_000432.4(MYL2):​c.84A>C​(p.Glu28Asp) variant causes a missense change involving the alteration of a non-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 (★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E28G) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYL2 NM_000432.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.47
• Publications: 0 publications found

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]

MYL2 Gene-Disease associations (from GenCC):

• hypertrophic cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• hypertrophic cardiomyopathy 10

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: ClinGen, G2P, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• myopathy, myofibrillar, 12, infantile-onset, with cardiomyopathy

  Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics
• congenital fiber-type disproportion myopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• dilated cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 16 uncertain in NM_000432.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 11 curated pathogenic missense variants (we use a threshold of 10). The gene has 2 curated benign missense variants. Gene score misZ: 0.39564 (below the threshold of 3.09). Trascript score misZ: 1.1124 (below the threshold of 3.09). GenCC associations: The gene is linked to hypertrophic cardiomyopathy 10, dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, hypertrophic cardiomyopathy, myopathy, myofibrillar, 12, infantile-onset, with cardiomyopathy, congenital fiber-type disproportion myopathy.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.863

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000432.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYL2	NM_000432.4	MANE Select	c.84A>C	p.Glu28Asp	missense	Exon 2 of 7	NP_000423.2
	MYL2	NM_001406745.1		c.84A>C	p.Glu28Asp	missense	Exon 2 of 6	NP_001393674.1
	MYL2	NM_001406916.1		c.27A>C	p.Glu9Asp	missense	Exon 2 of 7	NP_001393845.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYL2	ENST00000228841.15	TSL:1 MANE Select	c.84A>C	p.Glu28Asp	missense	Exon 2 of 7	ENSP00000228841.8
	MYL2	ENST00000713800.1		c.84A>C	p.Glu28Asp	missense	Exon 3 of 8	ENSP00000519106.1
	MYL2	ENST00000713803.1		c.84A>C	p.Glu28Asp	missense	Exon 3 of 8	ENSP00000519109.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hypertrophic cardiomyopathy 10 Uncertain:1

Dec 04, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with aspartic acid, which is acidic and polar, at codon 28 of the MYL2 protein (p.Glu28Asp). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with MYL2-related conditions. 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 disruptive. 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 v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
CardioboostCm	Pathogenic	1.0
BayesDel_addAF	Uncertain	0.16	D
BayesDel_noAF	Uncertain	-0.010
CADD	Uncertain	23
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.74	D
Eigen	Uncertain	0.46
Eigen_PC	Uncertain	0.37
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Uncertain	0.18	D
MetaRNN	Pathogenic	0.86	D
MetaSVM	Uncertain	0.24	D
MutationAssessor	Uncertain	2.3	M
PhyloP100		1.5
PrimateAI	Uncertain	0.77	T
PROVEAN	Uncertain	-2.8	D
REVEL	Pathogenic	0.67
Sift	Uncertain	0.017	D
Sift4G	Uncertain	0.0020	D
Polyphen		1.0	D
Vest4		0.87
MutPred		0.66		Gain of catalytic residue at I26 (P = 0.0071)
MVP		0.89
MPC		1.1
ClinPred		0.99	D
GERP RS		3.0
Varity_R		0.79
gMVP		0.84
Mutation Taster		=5/95	disease causing

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

Other links and lift over

dbSNP: rs397516410; hg19: chr12-111356917;