rs727504341

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PP2PP3_Moderate

The NM_000432.4(MYL2):​c.428C>T​(p.Pro143Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000242 in 1,613,640 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P143T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000025 ( 0 hom. )

Consequence

MYL2
NM_000432.4 missense

Scores

11
8

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7

Conservation

PhyloP100: 9.55

Publications

2 publications found
Variant links:
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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

PM1
In a domain EF-hand 3 (size 35) in uniprot entity MLRV_HUMAN there are 6 pathogenic changes around while only 1 benign (86%) in NM_000432.4
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, 0.91

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
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
MYL2
NM_000432.4
MANE Select
c.428C>Tp.Pro143Leu
missense
Exon 7 of 7NP_000423.2
MYL2
NM_001406745.1
c.386C>Tp.Pro129Leu
missense
Exon 6 of 6NP_001393674.1
MYL2
NM_001406916.1
c.371C>Tp.Pro124Leu
missense
Exon 7 of 7NP_001393845.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
MYL2
ENST00000228841.15
TSL:1 MANE Select
c.428C>Tp.Pro143Leu
missense
Exon 7 of 7ENSP00000228841.8
MYL2
ENST00000713800.1
c.428C>Tp.Pro143Leu
missense
Exon 8 of 8ENSP00000519106.1
MYL2
ENST00000713803.1
c.428C>Tp.Pro143Leu
missense
Exon 8 of 8ENSP00000519109.1

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
151950
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000201
AC:
5
AN:
248938
AF XY:
0.0000223
show subpopulations
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000449
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000253
AC:
37
AN:
1461690
Hom.:
0
Cov.:
32
AF XY:
0.0000275
AC XY:
20
AN XY:
727126
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53246
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000333
AC:
37
AN:
1111988
Other (OTH)
AF:
0.00
AC:
0
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.445
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000132
AC:
2
AN:
151950
Hom.:
0
Cov.:
31
AF XY:
0.0000270
AC XY:
2
AN XY:
74210
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41346
American (AMR)
AF:
0.00
AC:
0
AN:
15248
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5170
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
67978
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.00000000770867), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.400
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000609
Hom.:
0
Bravo
AF:
0.0000264
TwinsUK
AF:
0.000539
AC:
2
ALSPAC
AF:
0.00
AC:
0
ExAC
AF:
0.0000247
AC:
3

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:2
Sep 09, 2015
Blueprint Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

May 01, 2014
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The Pro143Leu variant in MYL2 has been identified by our laboratory in 1 African American teenager with HCM, who also carried a pathogenic variant in the MYBPC3 gene and had an earlier presentation than his mother, who only carried the MYBP C3 variant. This variant was absent from large population studies. Proline (Pro) at position 143 is highly conserved in evolution and the change to leucine (Leu ) was predicted to be pathogenic using a computational tool clinically validated by our laboratory. This tool's pathogenic prediction is estimated to be correct 94% of the time (Jordan 2011). Additional information is needed to fully assess the clinical significance of the Pro143Leu variant.

Hypertrophic cardiomyopathy 10 Uncertain:1
Dec 18, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 143 of the MYL2 protein (p.Pro143Leu). This variant is present in population databases (rs727504341, gnomAD 0.006%). This missense change has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 27532257, 37652022). ClinVar contains an entry for this variant (Variation ID: 177824). 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.

Hypertrophic cardiomyopathy 10;C5561937:Myopathy, myofibrillar, 12, infantile-onset, with cardiomyopathy Uncertain:1
Nov 22, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Hypertrophic cardiomyopathy Uncertain:1
Aug 06, 2024
All of Us Research Program, National Institutes of Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces proline with leucine at codon 143 of the MYL2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has been reported in an individual affected with hypertrophic cardiomyopathy (PMID: 27532257). This variant has also been reported in an individual from a cohort of participants that were not pre-selected for a personal or family history of cardiovascular disorders (PMID: 22958901). This variant has been identified in 7/280276 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance.

Cardiomyopathy, dilated, and heart failure Uncertain:1
Jun 26, 2025
Clinical Genetics Laboratory, Skane University Hospital Lund
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

ACMG criteria used: PP3

Cardiovascular phenotype Uncertain:1
Aug 30, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.P143L variant (also known as c.428C>T), located in coding exon 7 of the MYL2 gene, results from a C to T substitution at nucleotide position 428. The proline at codon 143 is replaced by leucine, an amino acid with similar properties. This alteration has been reported in the Framingham Heart Study cohort; however, clinical details were limited (Bick AG et al. Am J Hum Genet, 2012 Sep;91:513-9). Additionally, this alteration has also been detected in an individual who underwent genetic testing for hypertrophic cardiomyopathy, and in individual from a pediatric dilated cardiomyopathy cohort; however, clinical details were limited (Walsh R et al. Genet Med, 2017 02;19:192-203). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.36
CardioboostCm
Uncertain
0.78
BayesDel_addAF
Pathogenic
0.23
D
BayesDel_noAF
Pathogenic
0.22
CADD
Pathogenic
29
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.82
D
Eigen
Pathogenic
0.86
Eigen_PC
Pathogenic
0.79
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.91
D
M_CAP
Pathogenic
0.57
D
MetaRNN
Pathogenic
0.91
D
MetaSVM
Uncertain
0.48
D
MutationAssessor
Uncertain
2.9
M
PhyloP100
9.5
PrimateAI
Uncertain
0.74
T
PROVEAN
Pathogenic
-7.5
D
REVEL
Pathogenic
0.87
Sift
Pathogenic
0.0
D
Sift4G
Uncertain
0.0050
D
Polyphen
1.0
D
Vest4
0.83
MutPred
0.56
Gain of catalytic residue at A141 (P = 9e-04)
MVP
0.93
MPC
1.2
ClinPred
0.99
D
GERP RS
5.0
Varity_R
0.79
gMVP
0.80
Mutation Taster
=46/54
disease causing

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

Other links and lift over

dbSNP: rs727504341; hg19: chr12-111348954; COSMIC: COSV105849566; COSMIC: COSV105849566; API