12-110911081-T-G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP3_Moderate

The NM_000432.4(MYL2):c.497A>C(p.Asp166Ala) 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D166N) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 31)
• Consequence: MYL2 NM_000432.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.27

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 8 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain 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 chr12-110911081-T-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 31769.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.849

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYL2	NM_000432.4	c.497A>C	p.Asp166Ala	missense_variant	7/7	ENST00000228841.15
MYL2	NM_001406745.1	c.455A>C	p.Asp152Ala	missense_variant	6/6
MYL2	NM_001406916.1	c.440A>C	p.Asp147Ala	missense_variant	7/7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYL2	ENST00000228841.15	c.497A>C	p.Asp166Ala	missense_variant	7/7	1	NM_000432.4	P1
MYL2	ENST00000548438.1	c.455A>C	p.Asp152Ala	missense_variant	6/6	3
MYL2	ENST00000663220.1	c.440A>C	p.Asp147Ala	missense_variant	7/7

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hypertrophic cardiomyopathy 10 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 14, 2019

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 with MYL2-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces aspartic acid with alanine at codon 166 of the MYL2 protein (p.Asp166Ala). The aspartic acid residue is moderately conserved and there is a moderate physicochemical difference between aspartic acid and alanine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.42
CardioboostCm	Uncertain	0.62
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.13
Cadd	Uncertain	24
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.75	D;.
Eigen	Uncertain	0.41
Eigen_PC	Uncertain	0.43
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Pathogenic	0.54	D
MetaRNN	Pathogenic	0.85	D;D
MetaSVM	Uncertain	0.12	D
MutationAssessor	Uncertain	2.4	M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.73	T
PROVEAN	Uncertain	-4.2	D;D
REVEL	Pathogenic	0.80
Sift	Uncertain	0.0030	D;D
Sift4G	Uncertain	0.0060	D;D
Polyphen		0.75	P;.
Vest4		0.77
MutPred		0.46		Gain of catalytic residue at E163 (P = 0.1052);.;
MVP		0.88
MPC		1.0
ClinPred		0.99	D
GERP RS		5.0
Varity_R		0.92
gMVP		0.86

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

Publications

LitVar

Other links and lift over

dbSNP: rs199474815; hg19: chr12-111348885;