chr12-110911148-G-T

Variant names:

• chr12-110911148-G-T
• rs777689913
• NM_000432.4:c.430C>A

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.430C>A​(p.Pro144Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,710 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: MYL2 NM_000432.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 9.55

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 chain Myosin regulatory light chain 2, ventricular/cardiac muscle isoform (size 164) in uniprot entity MLRV_HUMAN there are 33 pathogenic changes around while only 3 benign (92%) in NM_000432.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.852

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYL2	NM_000432.4	c.430C>A	p.Pro144Thr	missense_variant	Exon 7 of 7	ENST00000228841.15	NP_000423.2
MYL2	NM_001406745.1	c.388C>A	p.Pro130Thr	missense_variant	Exon 6 of 6		NP_001393674.1
MYL2	NM_001406916.1	c.373C>A	p.Pro125Thr	missense_variant	Exon 7 of 7		NP_001393845.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYL2	ENST00000228841.15	c.430C>A	p.Pro144Thr	missense_variant	Exon 7 of 7	1	NM_000432.4	ENSP00000228841.8
MYL2	ENST00000548438.1	c.388C>A	p.Pro130Thr	missense_variant	Exon 6 of 6	3		ENSP00000447154.1
MYL2	ENST00000663220.1	c.373C>A	p.Pro125Thr	missense_variant	Exon 7 of 7			ENSP00000499568.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.00000402 AC: 1 AN: 248888 Hom.: 0 AF XY: 0.00000742 AC XY: 1 AN XY: 134700

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000897

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461710 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727142

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypertrophic cardiomyopathy 10 Uncertain:1

Oct 23, 2016

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces proline with threonine at codon 144 of the MYL2 protein (p.Pro144Thr). The proline residue is highly conserved and there is a small physicochemical difference between proline and threonine. In summary, this variant is a rare missense change with uncertain impact on protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. 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 do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). However, a computational algorithm designed to assess the pathogenicity of variants in MYL2 with regard to hypertrophic cardiomyopathy predicted this sequence change to be deleterious. The algorithm has a sensitivity of 94% and a specificity of 89% (PMID: 21310275). This variant is present in population databases (rs777689913, ExAC 0.002%) but has not been reported in the literature in individuals with a MYL2-related disease. -

Hypertrophic cardiomyopathy Uncertain:1

May 31, 2023

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	Benign	0.27
CardioboostCm	Uncertain	0.44
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Benign	0.37	T;.
Eigen	Uncertain	0.63
Eigen_PC	Uncertain	0.64
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.85	D;D
M_CAP	Uncertain	0.19	D
MetaRNN	Pathogenic	0.85	D;D
MetaSVM	Uncertain	0.040	D
MutationAssessor	Benign	1.7	L;.
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	-1.7	N;N
REVEL	Uncertain	0.57
Sift	Benign	0.12	T;T
Sift4G	Benign	0.13	T;T
Polyphen		0.92	P;.
Vest4		0.82
MVP		0.91
MPC		1.2
ClinPred		0.95	D
GERP RS		5.0
Varity_R		0.26
gMVP		0.69

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: rs777689913; hg19: chr12-111348952;