NM_000257.4:c.2722C>G

Variant names:

• chr14-23424107-G-C
• rs121913631
• NM_000257.4:c.2722C>G
• MYH7 p.Leu908Val

GermlineCancer (beta)

Variant summary

Our verdict is Uncertain significance.

+5 Uncertain · Hot

-7

-6

-1

0

+5

+6

+9

+10

BenignB

Likely BenignLB

UncertainVUS

Likely PathogenicLP

PathogenicP

The variant received 5 classification points (ACGS-UK Somatic Oncogenicity v2025). O3_SupportingO6_SupportingO7_ModerateO8_Supporting

The NM_000257.4(MYH7):c.2722C>G (p.Leu908Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a cumulative frequency of 0.00000372 (AC=6) in the gnomAD database across 1,614,104 control chromosomes (no homozygotes observed). The grpmax filtering allele frequency (95% CI) is 0.00000488. In-silico predictor (REVEL) classifies this variant as likely damaging/oncogenic. Splicing prediction tools (SpliceAI) predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic/Likely Pathogenic (★★★). ClinVar reports functional evidence for this variant: "SCV000692499: "In vitro assays suggest that the variant may impact myosin cross-bridge kinetics (Palmiter et al., 2000) and increase the velocity by which myosin translocated actin (Alpert NR, et al., 2005)."" and additional evidence is available in ClinVar. A different missense at the same amino acid position has been reported as Pathogenic/Likely Pathogenic in ClinVar: p.L908M: Likely_pathogenic (ClinVar VariationId 2763277, 1 star) Other variants at the same amino acid position have been reported in ClinVar (not pathogenic): p.L908= (synonymous): Likely_benign (ClinVar VariationId 763750, 1 star) This exact variant is curated in the UniProt human variants database as Uncertain Significance.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:17
• Conservation: PhyloP100: 2.98
• Publications: 26 publications found

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 Gene-Disease associations (from GenCC):

• dilated cardiomyopathy 1S

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, ClinGen, Ambry Genetics
• hypertrophic cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• hypertrophic cardiomyopathy 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• MYH7-related skeletal myopathy

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Orphanet, ClinGen
• myopathy, myosin storage, autosomal recessive

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• myopathy, myosin storage, autosomal dominant

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• Ebstein anomaly

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hyaline body myopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• left ventricular noncompaction

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen, G2P
• congenital heart disease

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

Classification according to ACGS-UK Somatic Oncogenicity v2025

Specifications for MYH7 are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Classification was made for transcript:

Our verdict: Uncertain_significance. The variant received 5 points.

Apply	Criterion Code & Title / Strength	Strength	Rationale / Clinical Context
	O3Absent or very rare in population		Very rare in gnomAD (popmax AF <0.01%) — O3 supporting; GnomAD effective popmax AF = 0.000005 — very rare (O3 supporting [+1])
	O6Computational evidence supports deleterious effect		Computational evidence supports a deleterious/oncogenic effect; Missense variant — primary computational scorer supports an oncogenic/deleterious effect
	O7Mutational hotspot or critical domain		Moderate: ≥10 same AA change, or strong functional domain signal; No cancerhotspots.org hit at this position; UniProt domain: 106 pathogenic, 0 benign (OR vs. background: 1065.0).; ±8 AA neighbourhood: 20 pathogenic, 0 benign (OR vs. background: 205.0); Variant does not impact splicing — splice-hotspot path not applicable
	O8Missense constraint in gene or region		Missense in gene/domain constrained for missense variation where missense is common disease mechanism (O8 supporting); Gene/disease mechanism: missense is a common mechanism of oncogenesis; gnomAD missense Z-score: 6.81 (threshold ≥3.09 for constraint); Domain-level constraint: variant is in a critically constrained functional domain (IS_AT_CRITICAL_DOMAIN)

Variant Effect in Transcripts

Automated classification analysis was done for transcript: NM_000257.4. You can select a different transcript below to see updated classification assignments.

RefSeq Transcripts

Sel.	Gene / Transcript	Tags	HGVSc / HGVSp	Effect	Exon rank	Protein / UniProt
	MYH7 NM_000257.4	MANE Select	c.2722C>G p.Leu908Val	missense	Exon 23 of 40	Prot: NP_000248.2 UniProt:
	MYH7 NM_001407004.1		c.2722C>G p.Leu908Val	missense	Exon 22 of 39	Prot: NP_001393933.1 UniProt:

MYH7 NM_000257.4

MANE Select

HGVSc / HGVSpc.2722C>Gp.Leu908Val

Exon rankExon 23 of 40

missense

Prot: NP_000248.2UniProt: P12883

MYH7 NM_001407004.1

HGVSc / HGVSpc.2722C>Gp.Leu908Val

Exon rankExon 22 of 39

missense

Prot: NP_001393933.1UniProt: P12883

Ensembl Transcripts

Sel.	Gene / Transcript	Tags	HGVSc / HGVSp	Effect	Exon rank	Protein / UniProt
	MYH7 ENST00000355349.4	TSL:1MANE Select	c.2722C>G p.Leu908Val	missense	Exon 23 of 40	Prot: ENSP00000347507.3 UniProt:
	MYH7 ENST00000858540.1		c.2722C>G p.Leu908Val	missense	Exon 23 of 40	Prot: ENSP00000528599.1 UniProt:
	MYH7 ENST00000965955.1		c.2722C>G p.Leu908Val	missense	Exon 23 of 40	Prot: ENSP00000636014.1 UniProt:

MYH7 ENST00000355349.4

TSL:1MANE Select

HGVSc / HGVSpc.2722C>Gp.Leu908Val

Exon rankExon 23 of 40

missense

Prot: ENSP00000347507.3UniProt: P12883

MYH7 ENST00000858540.1

HGVSc / HGVSpc.2722C>Gp.Leu908Val

Exon rankExon 23 of 40

missense

Prot: ENSP00000528599.1UniProt: A0ACI8PLM0

MYH7 ENST00000965955.1

HGVSc / HGVSpc.2722C>Gp.Leu908Val

Exon rankExon 23 of 40

missense

Prot: ENSP00000636014.1UniProt: A0ACI8PLM0

Frequencies

Allele frequencies (AF), counts (AC/AN), homozygotes and coverage

Common (AF > 0.05 / Hom > 5)

Rare (AF ≤ 0.0001 / Hom ≤ 1)

Source / population	AF	AC	Hom	AN	Coverage
Global population databases 5 sources Large-scale international reference populations
GnomAD3 genomes	AF: 0.0000131	AC:2	Hom:0	AN:152222	Cov:32
GnomAD4 exome	AF: 0.00000274	AC:4	Hom:0	AN:1461882	Cov:34
GnomAD4 genome	AF: 0.0000131	AC:2	Hom:0	AN:152222	Cov:32
TOPMed (Bravo)	AF: 0.0000113	AC:3	Hom:0	AN:264690	Cov:
ALFA (dbGaP/dbSNP Allele Frequency Aggregator)	AF: 0.0000523	AC:2	Hom:0	AN:38206	Cov:

Showing 5 sources

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
4	-	-	Hypertrophic cardiomyopathy (4)
4	-	-	not provided (4)
3	-	-	Hypertrophic cardiomyopathy 1 (3)
2	-	-	Cardiomyopathy (2)
2	-	-	Cardiovascular phenotype (2)
2	-	-	Primary familial hypertrophic cardiomyopathy (2)

Computational Scores

Algorithm	Calibrated pred.	Score	Prediction
AlphaGenome AVI	Pathogenic	23
AlphaMissense	Uncertain	0.42
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.43
CADD	Uncertain	24
CardioboostCm	Pathogenic	1.0
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.86	D
Eigen	Pathogenic	0.91
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Uncertain	0.96	D
FuncVEP CTI	Pathogenic	0.93
GPN-Star LLR	N/A	-9.0
GPN-Star score	N/A	9.0
LIST_S2	Uncertain	0.91	D
M_CAP	Pathogenic	0.94	D
MetaRNN	Pathogenic	0.89	D
MetaSVM	Pathogenic	1.0	D
Mutation Taster	N/A	2/98	disease causing (ClinVar)
MutationAssessor	Pathogenic	4.5	H
PhyloP100	Benign	3.0
popEVE	Benign	-3.4
PrimateAI	Pathogenic	0.81	D
PROVEAN	Uncertain	-2.4	N
REVEL	Pathogenic	0.78
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Varity_R	N/A	0.54
VESM-3B	Benign	-10

Showing 29 of 29 scores

Splicing Scores

Algorithm	Calibrated pred.	Score	Prediction
Pangolin (max)	Benign	0.020
SpliceAI score (max)	Benign	0.0	Details are displayed if max score is > 0.2

Showing 2 of 2 scores

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

MaveDB functional evidence

MaveDB is a public repository of laboratory assays that test the effect of thousands of variants at once — treat this as supporting research data and interpret it with great caution; it is not a clinical classification.

No MaveDB functional evidence found for this variant.

Other links and lift over

dbSNP: rs121913631;

hg19: chr14-23893316;

ACMG debug oncogenicity

ACGS debug oncogenicity

ACMG debug germline

Submit to ClinVar