rs727503192
Variant summary
Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000256.3(MYBPC3):c.1999_2000delCTinsG(p.Leu667AspfsTer15) variant causes a frameshift, missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. L667L) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.
Frequency
Consequence
NM_000256.3 frameshift, missense
Scores
Clinical Significance
Conservation
Publications
- hypertrophic cardiomyopathyInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- hypertrophic cardiomyopathy 4Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
- left ventricular noncompaction 10Inheritance: AR, AD Classification: DEFINITIVE, MODERATE, LIMITED Submitted by: Ambry Genetics
- familial isolated dilated cardiomyopathyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- arrhythmogenic right ventricular cardiomyopathyInheritance: AD Classification: LIMITED Submitted by: ClinGen
- atrial fibrillationInheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
- dilated cardiomyopathyInheritance: AD Classification: LIMITED Submitted by: ClinGen
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ACMG classification
Our verdict: Pathogenic. The variant received 18 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
MYBPC3 | ENST00000545968.6 | c.1999_2000delCTinsG | p.Leu667AspfsTer15 | frameshift_variant, missense_variant | Exon 21 of 35 | 5 | NM_000256.3 | ENSP00000442795.1 | ||
MYBPC3 | ENST00000399249.6 | c.1999_2000delCTinsG | p.Leu667AspfsTer15 | frameshift_variant, missense_variant | Exon 20 of 34 | 5 | ENSP00000382193.2 | |||
MYBPC3 | ENST00000544791.1 | n.1999_2000delCTinsG | non_coding_transcript_exon_variant | Exon 21 of 27 | 5 | ENSP00000444259.1 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Hypertrophic cardiomyopathy Pathogenic:3
The Leu667fs variant in MYBPC3 has been identified by our laboratory in 2 Hispan ic individuals with HCM. Data from large population studies is insufficient to a ssess the frequency of this variant. This frameshift variant is predicted to alt er the protein?s amino acid sequence beginning at position 667 and lead to a pre mature termination codon 15 amino acids downstream. This alteration is then pred icted to lead to a truncated or absent protein. Heterozygous loss of function of the MYBPC3 gene is an established disease mechanism in individuals with HCM. In summary, this variant meets our criteria to be classified as pathogenic (http:/ /pcpgm.partners.org/LMM) based on the predicated impact of the variant. -
This variant is predicted to result in loss of protein function through nonsense-mediated or protein truncation. Loss of function is an established mechanism of disease. This prediction has not been confirmed by functional studies. This variant has been reported in multiple individuals with hypertrophic cardiomyopathy (PMID: 7532257, 25611685, 20474083, 28840316, 30297972, 32841044) .This variant is absent from or rare in large population databases, including the Genome Aggregation Database (http://gnomad.broadinstitute.org/). -
This sequence change creates a premature translational stop signal (p.Leu667Aspfs*15) in the MYBPC3 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MYBPC3 are known to be pathogenic (PMID: 19574547). Information on the frequency of this variant in the gnomAD database is not available, as this variant may be reported differently in the database. This premature translational stop signal has been observed in individual(s) with hypertrophic or dilated cardiomyopathy (PMID: 20474083, 24793961, 27532257). For these reasons, this variant has been classified as Pathogenic. -
Hypertrophic cardiomyopathy 4;C3715165:Left ventricular noncompaction 10 Pathogenic:2
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The c.1999_2000delCTinsG (p.Leu667AspfsTer15) variant identified in the MYBPC3 gene resulting in a frameshift at amino acid 667/1275 (exon 21/35) is predicted to lead to the premature termination of the protein 15 amino acids downstream and is expected to result in either an abnormal, truncated protein product or loss of protein through nonsense-mediated mRNA decay. The variant has been reported in several individuals affected with hypertrophic cardiomyopathy in the literature (PMID: 20474083, 24793961, 27532257). The variant has 0.0001117 allele frequency in the gnomAD (v3.1.2) database (17 out of 152182 heterozygous alleles, no homozygotes). The variant is reported as Pathogenic by multiple submitters in ClinVar (Variation ID: 164091). Based on the available evidence, the heterozygous c.1999_2000delCTinsG (p.Leu667AspfsTer15) variant identified in the MYBPC3 gene is reported as Likely Pathogenic. -
Cardiomyopathy Pathogenic:1
This variant deletes 3 nucleotides in exon 21 of the MYBPC3 gene, creating a frameshift and premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. This variant has been reported in individuals affected with hypertrophic cardiomyopathy (PMID: 24793961, 24835277, 27532257, 30297972, 32841044) and in an individual affected with dilated cardiomyopathy (PMID: 20474083). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of MYBPC3 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -
not provided Pathogenic:1
Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Reported in ClinVar as a pathogenic variant (ClinVar Variant ID# 164091; ClinVar); Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 20474083, 24793961, 27532257, 27535533) -
Hypertrophic cardiomyopathy 4 Pathogenic:1
This variant leads to a translational frameshift and the introduction of a premature termination codon 15 residues downstream. The variant transcript is predicted to be unstable and degraded by nonsense-mediated decay. Loss of expression of one allele of MYBPC3 is a well-established mechanism of disease for hypertrophic cardiomyopathy (Marston 2009). This variant has been reported in the literature in multiple individuals with hypertrophic or dilated cardiomyopathy (Zimmerman 2010, Bos 2014, Walsh 2017). This variant has an overall allele frequency of 0.00004 in the Broad Institute gnomAD Browser (https://gnomad.broadinstitute.org/). Thus, this variant is interpreted as pathogenic. PVS1 -
Cardiovascular phenotype Pathogenic:1
The c.1999_2000delCTinsG pathogenic mutation, located in coding exon 21 of the MYBPC3 gene, results from the deletion of two nucleotides and insertion of one nucleotide causing a translational frameshift with a predicted alternate stop codon (p.L667Dfs*15). This alteration has been reported in subjects with dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM) (Zimmerman RS et al. Genet. Med., 2010 May;12:268-78; Bos JM et al. Mayo Clin. Proc., 2014 Jun;89:727-37; Walsh R et al. Genet. Med., 2017 02;19:192-203). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at