rs397515894
Variant summary
Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000256.3(MYBPC3):c.1235_1236delTT(p.Phe412fs) variant causes a frameshift 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 Pathogenic (★★). Variant results in nonsense mediated mRNA decay.
Frequency
Consequence
NM_000256.3 frameshift
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.1235_1236delTT | p.Phe412fs | frameshift_variant | Exon 15 of 35 | 5 | NM_000256.3 | ENSP00000442795.1 | ||
| MYBPC3 | ENST00000399249.6 | c.1235_1236delTT | p.Phe412fs | frameshift_variant | Exon 14 of 34 | 5 | ENSP00000382193.2 | |||
| MYBPC3 | ENST00000544791.1 | n.1235_1236delTT | non_coding_transcript_exon_variant | Exon 15 of 27 | 5 | ENSP00000444259.1 |
Frequencies
GnomAD3 genomes Cov.: 33
GnomAD4 genome Cov.: 33
ClinVar
Submissions by phenotype
not provided Pathogenic:4
Identified in multiple patients with HCM referred to GeneDx and in published literature (PMID: 12707239, 15519027, 18957093, 24111713, 24510615, 29121657); Nonsense 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; Not observed at significant frequency in large population cohorts (gnomAD); Also known as del TT[10512-10513] and I411 fs/0; This variant is associated with the following publications: (PMID: 24111713, 12707239, 18957093, 15519027, 29121657, 37652022, 35653365, 24510615) -
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PM2, PS4_moderate, PVS1 -
Hypertrophic cardiomyopathy Pathogenic:2
The p.Phe412X variant in MYBPC3 has been reported in >3 individuals with HCM (Richard 2003, Van Driest 2004, LMM data) and was absent from large population studies. It has also been reported in ClinVar (Variant ID: 42514). This variant is a deletion of 2 bases resulting in a premature termination codon at position 412, which is predicted 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, the p.Phe412X variant meets criteria to be classified as pathogenic for autosomal dominant HCM. ACMG/AMP criteria applied: PVS1, PM2, PS4_Supporting. -
This sequence change creates a premature translational stop signal (p.Phe412*) 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). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individuals with hypertrophic cardiomyopathy (PMID: 12707239, 18957093, 24111713, 24510615). ClinVar contains an entry for this variant (Variation ID: 42514). For these reasons, this variant has been classified as Pathogenic. -
Cardiovascular phenotype Pathogenic:2
The c.1235_1236delTT pathogenic mutation, located in coding exon 15 of the MYBPC3 gene, results from a deletion of two nucleotides at nucleotide positions 1235 to 1236, causing a translational frameshift with a predicted alternate stop codon (p.F412*). This alteration, also referred to as del TT[10512-10513] or I411 fs/0, has been reported in individuals with hypertrophic cardiomyopathy (Richard P et al. Circulation, 2003 May;107:2227-32; Van Driest SL et al. J. Am. Coll. Cardiol., 2004 Nov;44:1903-10). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). 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. -
Variant summary: The MYBPC3 c.1235_1236delTT (p.Phe412Terfs) variant is a frameshift mutation predicted to cause loss of normal protein function due to production of a truncated protein or by the absence of the protein product due to nonsense-mediated mRNA decay. Mutation taster predicts a damaging outcome for this variant. It was not found in 102952 control chromosomes while it was reported in several patients with HCM from the literature. In one family, the variant co-segregated with disease, indicating pathogenicity. Truncations downstream of this position have been classified as pathogenic by our laboratory (e.g. p.Leu667fs), further supporting a deleterious outcome. In addition, clinical diagnostic laboratories and reputable databases classified this variant as Pathogenic. Taken together, this variant was classified as Pathogenic. -
Cardiomyopathy Pathogenic:1
This variant deletes 2 nucleotides in exon 15 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. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in several individuals and in a family affected with hypertrophic cardiomyopathy or referred for hypertrophic cardiomyopathy genetic testing (PMID: 12707239, 18957093, 24111713, 24510615). 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at