chr12-110915783-G-T

Variant names:

• chr12-110915783-G-T
• rs876657894
• NM_000432.4:c.101C>A

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1 PM2 PP2

The NM_000432.4(MYL2):​c.101C>A​(p.Thr34Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T34I) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: MYL2 NM_000432.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.60
• 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: Uncertain_significance. The variant received 5 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYL2	NM_000432.4	c.101C>A	p.Thr34Asn	missense_variant	Exon 3 of 7	ENST00000228841.15	NP_000423.2
MYL2	NM_001406916.1	c.44C>A	p.Thr15Asn	missense_variant	Exon 3 of 7		NP_001393845.1
MYL2	NM_001406745.1	c.94-1459C>A		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.101C>A	p.Thr34Asn	missense_variant	Exon 3 of 7	1	NM_000432.4	ENSP00000228841.8

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hypertrophic cardiomyopathy 10 Uncertain:1

Apr 15, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals affected with MYL2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces threonine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 34 of the MYL2 protein (p.Thr34Asn). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.56
CardioboostCm	Uncertain	0.33
BayesDel_addAF	Benign	-0.012	T
BayesDel_noAF	Benign	-0.26
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.47	T
Eigen	Uncertain	0.31
Eigen_PC	Uncertain	0.42
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.90	D
M_CAP	Benign	0.039	D
MetaRNN	Uncertain	0.66	D
MetaSVM	Benign	-0.86	T
MutationAssessor	Benign	-0.095	N
PhyloP100		9.6
PrimateAI	Uncertain	0.78	T
PROVEAN	Uncertain	-2.6	D
REVEL	Uncertain	0.29
Sift	Benign	0.69	T
Sift4G	Benign	0.55	T
Polyphen		0.96	D
Vest4		0.63
MutPred		0.35		Gain of catalytic residue at N39 (P = 0.0835);
MVP		0.84
MPC		1.1
ClinPred		0.97	D
GERP RS		5.1
Varity_R		0.84
gMVP		0.84
Mutation Taster		=41/59	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: rs876657894; hg19: chr12-111353587;