rs397515926
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000256.3(MYBPC3):c.1800delA(p.Lys600AsnfsTer2) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000697 in 1,435,652 control chromosomes in the GnomAD database, with no homozygous occurrence. 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
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ACMG classification
Verdict is Pathogenic. Variant got 18 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
MYBPC3 | ENST00000545968.6 | c.1800delA | p.Lys600AsnfsTer2 | frameshift_variant | Exon 19 of 35 | 5 | NM_000256.3 | ENSP00000442795.1 | ||
MYBPC3 | ENST00000399249.6 | c.1800delA | p.Lys600AsnfsTer2 | frameshift_variant | Exon 18 of 34 | 5 | ENSP00000382193.2 | |||
MYBPC3 | ENST00000544791.1 | n.1800delA | non_coding_transcript_exon_variant | Exon 19 of 27 | 5 | ENSP00000444259.1 |
Frequencies
GnomAD3 genomes Cov.: 33
GnomAD3 exomes AF: 0.00000491 AC: 1AN: 203524Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 109684
GnomAD4 exome AF: 6.97e-7 AC: 1AN: 1435652Hom.: 0 Cov.: 36 AF XY: 0.00 AC XY: 0AN XY: 711590
GnomAD4 genome Cov.: 33
ClinVar
Submissions by phenotype
not provided Pathogenic:4
Note this variant was found in clinical genetic testing performed by one or more labs who may also submit to ClinVar. Thus any internal case data may overlap with the internal case data of other labs. The interpretation reviewed below is that of the Stanford Center for Inherited Cardiovascular Disease. p.Lys600AsnfsX2 (p.K600NfsX2, p.K600Nfs, p.Lys600Nfs c.1800delA) in exon 19 of the MYBPC3 gene (NM_000256.3). Given that frameshift variants in this gene are a common cause of HCM and that there is strong case and segregation data, we consider this variant very likely disease causing. The variant has been seen in at least 11 unrelated cases of (not including this patient's family). Richard et al (2003) reported the variant in one of 197 unrelated HCM patients from their French cohort. Most were of European ancestry. They analyzed 9 sarcomere genes. Note they refer to the variant as del A 12413 (I found multiple sources that map this as the same variant as p.Lys600AsnfsX2). No segregation data was provided. Brito et al (2012) observed the variant in one of 77 HCM patients from their Portuguese cohort that underwent analysis of 5 sarcomere genes. They note that segregation analysis was performed but don't give specific data for this variant. I found a Spanish publication that appears to be about preimplantation genetic diagnosis for this variant (Vendrell et al 2009). Rodriguez-Garcia et al (2010) reported the variant in two brothers with HCM from their Spanish cohort of 130 HCM patients. They only analyzed MYBPC3 in this study. The same group included a patient with this variant in a paper on conduction system disease in HCM (Barriales-Villa et al 2010). Unfortunately insufficient case details are available to determine if it is the same patient described in the other report. This group also published a very interesting family with a father and daughter with HCM and this variant and mother and son with hypertrabeculation (Ortiz et al 2009). The son did not carry the variant and presumably inherited hypertrabeculation from his mother. Interestingly, the authors note that they have a total of 8 families with HCM and this variant with 21 carriers and 90% penetrance by 30 years of age (also reported in a poster, Ortiz et al, http://spo.escardio.org/eslides/view.aspx?eevtid=33&fp=3253). There were three different families with three affected members with the variant, including one set of three first cousins. It is in ClinVar with a submission from LMM, classifying it as pathogenic, but not including internal case data (SCV000059083). Michels et al (2011) observed the variant in 1 of 327 unrelated Dutch HCM patients. No individual ancestry or phenotype data was reported. They only analyzed MYBPC3. This is a frame-shifting variant that creates a premature stop codon 2 codons downstream of the variant. The variant is expected to either cause a truncated protein or a completely absent protein due to nonsense-mediated mRNA decay. Many other frameshift and null variants have been identified in MYBPC3 in association with cardiomyopathy (ex. p.Trp792fs, p.Pro794fs, p.Lys1065fs, p.Cys1202fs, p.Pro1208fs, p.Trp1098ter, p.Glu1096ter, p.Cys1124ter, p.Gln1233ter). Furthermore, these types of variants in MYBPC3 are not seen in individuals without cardiomyopathy (Pan et al 2012).. In total the variant has not been seen in ~6800 published controls and individuals from publicly available population datasets. The variant is not listed in the NHLBI Exome Sequencing Project dataset, which currently includes variant calls on ~6500 Caucasian and African American individuals (as of July 15th, 2014). Note that this dataset does not match the patient's ancestry (Hispanic). The variant is listed in dbSNP (rs397515926), however the only submission is from LMMM. The variant was not observed in the following published control samples: 100 healthy adults (Richard et al 2003), 200 controls (Rodriguez-Garcia et al 2010). -
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Identified in multiple unrelated patients with HCM referred for genetic testing at GeneDx and in published literature (PMID: 12707239, 22857948, 27532257); 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; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 22857948, 27153395, 27532257, 31589614, 37652022, 20433692, 20738943, 12707239, 37317833) -
Hypertrophic cardiomyopathy Pathogenic:3
This variant deletes 1 nucleotide in exon 19 of the Ig-like domain C4 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: 12707239, 20433692, 20738943, 22857948, 27532257, 33495597). This variant has been identified in 1/203524 chromosomes 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. -
This sequence change creates a premature translational stop signal (p.Lys600Asnfs*2) 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 present in population databases (rs397515926, gnomAD 0.003%). This premature translational stop signal has been observed in individuals with hypertrophic cardiomyopathy (PMID: 12707239, 20433692, 22857948, 27532257). ClinVar contains an entry for this variant (Variation ID: 42568). For these reasons, this variant has been classified as Pathogenic. -
The p.Lys600fs variant in MYBPC3 has been identified by our laboratory in 2 adul ts with HCM. This frameshift variant is predicted to alter the protein?s amino a cid sequence beginning at position 600 and lead to a premature termination codon 2 amino acids downstream. This alteration is then predicted to lead to a trunca ted or absent protein. Heterozygous loss of function of the MYBPC3 gene is an es tablished disease mechanism in HCM patients. In summary, this variant meets crit eria to be classified as pathogenic (http://pcpgm.partners.org/LMM) based upon c onsistency with the established disease causing mechanism. -
Hypertrophic cardiomyopathy 4 Pathogenic:2
The inherited c.1800del (p.Lys600AsnfsTer2) variant identified in the MYBPC3 gene is the deletion of a single nucleotide resulting in a frameshift at amino acid 600/1275 (exon 19/35) and is predicted to lead to the premature termination of the protein 2 amino acids downstream. This variant is absent from gnomAD(v3.1.1) suggesting it is not a common benign variant in the populations represented in that database. Loss-of-function variants in MYBPC3 are known to be pathogenic [PMID: 19574547]. The c.1800del (p.Lys600AsnfsTer2) variant is reported in ClinVar as Pathogenic by multiple submitters (VarID: 42568) and has been reported in several individuals affected with hypertrophic cardiomyopathy in the literature [PMID: 12707239, 20433692, 22857948, 27532257, 20738943]. Given this variant is predicted to lead to the premature termination of the protein, its presence in affected individuals in the literature, and absence in population databases, the c.1800del (p.Lys600AsnfsTer2) variant identified in the MYBPC3 gene is reported as Pathogenic. -
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Cardiomyopathy Pathogenic:1
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Cardiovascular phenotype Pathogenic:1
The c.1800delA pathogenic mutation, located in coding exon 19 of the MYBPC3 gene, results from a deletion of one nucleotide at nucleotide position 1800, causing a translational frameshift with a predicted alternate stop codon (p.K600Nfs*2). This alteration (also known as g.12413delA) was reported in two individuals with hypertrophic cardiomyopathy (Richard P et al. Circulation 2003; 107(17):2227-32; Brito D et al. Rev Port Cardiol 2012; 31(9):577-87). 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