14-23430997-G-T

Position:

chr14-23430997-G-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2PM5PP2PP3_ModeratePP5

The NM_000257.4(MYH7):c.799C>A(p.Leu267Ile) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L267V) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

MYH7
NM_000257.4 missense, splice_region

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:1

Conservation

PhyloP100: 6.57

Variant links:

Genes affected

MYH7 (HGNC:7577): (myosin heavy chain 7) Muscle myosin is a hexameric protein containing 2 heavy chain subunits, 2 alkali light chain subunits, and 2 regulatory light chain subunits. This gene encodes the beta (or slow) heavy chain subunit of cardiac myosin. It is expressed predominantly in normal human ventricle. It is also expressed in skeletal muscle tissues rich in slow-twitch type I muscle fibers. Changes in the relative abundance of this protein and the alpha (or fast) heavy subunit of cardiac myosin correlate with the contractile velocity of cardiac muscle. Its expression is also altered during thyroid hormone depletion and hemodynamic overloading. Mutations in this gene are associated with familial hypertrophic cardiomyopathy, myosin storage myopathy, dilated cardiomyopathy, and Laing distal myopathy. [provided by RefSeq, May 2022]

MYH7 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr14-23430997-G-C is described in Lovd as [Likely_pathogenic].

PP2

Missense variant in gene, where missense usually causes diseases (based on misZ statistic), MYH7. . Gene score misZ: 3.9329 (greater than the threshold 3.09). Trascript score misZ: 6.7889 (greater than threshold 3.09). The gene has 341 curated pathogenic missense variants (we use a threshold of 10). The gene has 16 curated benign missense variants. GenCC has associacion of the gene with hyaline body myopathy, MYH7-related skeletal myopathy, dilated cardiomyopathy 1S, congenital myopathy 7A, myosin storage, autosomal dominant, dilated cardiomyopathy, left ventricular noncompaction, myopathy, myosin storage, autosomal dominant, hypertrophic cardiomyopathy, congenital heart disease, Ebstein anomaly, arrhythmogenic right ventricular cardiomyopathy, myopathy, myosin storage, autosomal recessive, hypertrophic cardiomyopathy 1, familial isolated dilated cardiomyopathy.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.931

PP5

Variant 14-23430997-G-T is Pathogenic according to our data. Variant chr14-23430997-G-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1203583.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYH7	NM_000257.4 link	c.799C>A	p.Leu267Ile	missense_variant, splice_region_variant	10/40	ENST00000355349.4	NP_000248.2	P12883
MYH7	NM_001407004.1 link	c.799C>A	p.Leu267Ile	missense_variant, splice_region_variant	9/39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4 link	c.799C>A	p.Leu267Ile	missense_variant, splice_region_variant	10/40	1	NM_000257.4	ENSP00000347507.3		P12883

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

Data not reliable, filtered out with message: AC0

AF:

0.00

AC:

AN:

1456578

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

724998

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:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Aug 09, 2019

Has not been previously published as pathogenic or benign to our knowledge; Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function -

Hypertrophic cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 22, 2023

This sequence change replaces leucine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 267 of the MYH7 protein (p.Leu267Ile). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with MYH7-related conditions. ClinVar contains an entry for this variant (Variation ID: 1203583). 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. This variant is found within a region of MYH7 between codons 181 and 937 that contains the majority of the myosin head domain. Missense variants in this region have been shown to be significantly overrepresented in individuals with hypertrophic cardiomyopathy (PMID: 27532257). 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 v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.95

CardioboostCm

Pathogenic

1.0

BayesDel_addAF

Pathogenic

0.26

BayesDel_noAF

Uncertain

0.13

CADD

Pathogenic

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.84

Eigen

Uncertain

0.35

Eigen_PC

Uncertain

0.29

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.95

M_CAP

Pathogenic

0.99

MetaRNN

Pathogenic

0.93

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

4.1

PrimateAI

Pathogenic

0.85

PROVEAN

Benign

-1.7

REVEL

Pathogenic

0.82

Sift

Uncertain

0.0010

Sift4G

Uncertain

0.0020

Polyphen

0.0080

Vest4

0.81

MutPred

0.74

Gain of catalytic residue at L268 (P = 0.0061);

MVP

0.96

MPC

2.2

ClinPred

0.94

GERP RS

3.6

Varity_R

0.84

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

No publications associated with this variant yet.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over